Pressure accumulator

ABSTRACT

The fixed or variable displacement hydraulic motor-pump ( 1 ) includes a motor-pump central rotor ( 3 ) in which a hydraulic cylinder ( 14 ) is arranged, the rotor ( 3 ) being in sealed contact with an input-output spool valve ( 43 ) connecting the cylinder ( 14 ) with a motor-pump frame ( 2 ) while a hydraulic piston ( 13 ) moves in the cylinder ( 14 ) to push, using a hydraulic piston guided plunger ( 18 ), a tangential arm ( 22 ) articulated in the central rotor ( 3 ), and a tangential arm antifriction roller ( 28 ) on a motor-pump peripheral rotor ( 29 ) synchronized in rotation with the motor-pump central rotor ( 3 ).

The present invention relates to a hydraulic motor-pump with fixed orvariable displacement.

Hydraulic pumps, hydraulic motor-pumps and hydraulic motors are used inmany industrial and household applications and may, under certainconditions, also be used as a means for transmitting power between theheat or electric engine of motor vehicles and the wheels of saidvehicles. Various industrial and household applications could thusbenefit greatly from a hydraulic motor-pump offering a high output at amoderate cost. It is nevertheless in the field of automobile propulsionthat the positive environmental, energy and economic impact of such ahydraulic motor-pump would be the most obvious.

The large majority of motor vehicles driving throughout the world arepropelled by reciprocating internal combustion heat engines operatingprimarily with oil-based fuels. For environmental, energy and economicreasons, reducing motor vehicle fuel consumption and the associatedcarbon dioxide emissions is a priority in most countries across theglobe. Consequently, reciprocating internal combustion motor vehicleengines are subject to constant improvements to increase their output,in particular during everyday use.

Progress is not, however, limited to the heat engine itself: reducingthe weight of motor vehicles, their aerodynamic drag and the rollingresistance of their tires also contributes to reducing the per-kilometerfuel consumption of said vehicles, by reducing the work their heatengines must supply to propel them. The use of onboard equipment with ahigh energy output also contributes to reducing the fuel consumption ofmotor vehicles, whether that equipment is dedicated to air conditioningfor the passenger compartment, power steering, lighting, or informationand communication.

Aside from the heat engine itself, at least four other strategies allowa noticeable improvement of the energy output of a motor vehicle:

-   -   Reducing friction losses produced by the members that transmit        the mechanical work produced by the heat engine of said vehicle        to its wheels;    -   Continuously optimizing the ratio of the transmission connecting        said heat engine to the drive wheels of said vehicle such that        said engine always works as close as possible to its operating        point offering the best energy output;    -   Temporarily storing all or part of the mechanical work produced        by the heat engine when its output is high, said work then being        recovered so as to move the motor vehicle in the power ranges        where the output of said engine is ordinarily low, so as to        avoid using said engine in those ranges;    -   Recovering the largest possible portion of the kinetic energy of        the motor vehicle during braking or deceleration thereof by        replacing, as much as possible, the use of friction brakes,        which dissipate said energy as a pure loss in the form of heat,        by storing said energy in a form that can be reused in the        reacceleration phase of said vehicle, the storage device for        said energy having to offer the best possible output both in        terms of storage and recovery, and having to have a storage and        recovery power such that the greatest amount of kinetic energy        of the vehicle can be recovered, then released.

These four strategies are found alone or in combination in various typesof transmissions that can be combined with various heat-electric,heat-pneumatic or heat-hydraulic hybrid devices, each configurationinvolving a compromise between various advantages and drawbacks, withoutany being fully satisfactory in practice.

At least two types of transmission are used in the context of motorvehicle propulsion: discrete ratio transmissions based on cluster gears,and continuously variable transmissions primarily based on belts,rollers or variable displacement hydraulic motor-pumps. Discrete ratiotransmissions may be controlled manually or automatically, whereascontinuously variable transmissions are generally controlledautomatically.

The traditional gear transmissions have a high output, since the workthat they transmit goes through smaller number of pairs of involutepinions. Furthermore, said transmissions are coupled with the heatengine using a dry disc clutch that only dissipates the energy duringgear shifting, and in a small quantity. These transmissions aregenerally actuated by the driver, who selects the ratios thereofmanually, at his own discretion. Said gear transmissions are known as“manual transmissions”. They still make up the majority of automobileproduction worldwide, since they offer the best mechanical output of alltransmissions combined and are inexpensive to produce.

It is possible to optimize the use of the transmission ratios oftraditional transmissions using a maximum output or maximum powercriterion of the heat engine. This may be done by allowing software runby a microprocessor to choose the engaged ratio. In that case, anautomaton replaces the driver, whose clutch pedal and gear shifter arereplaced by electromechanical, electro-hydraulic or electro-pneumaticactuators acting directly on the clutch and the selection ranges of thetransmission ratios. These “automated manual transmissions” offer bothmaximum mechanical output and good optimization of the operating pointsof the engine.

The main drawback of this configuration is relative slowness in shiftinggears, which results—for the vehicle's driver—in an unpleasant sensationof loss of continuity in the transmission of the power. This problem isgreatly attenuated, or even practically eliminated, if quick actuatorsare used, which cooperate with synchro rings that are also quick. Theproblem with the latter solutions is their cost, which limits them totransmissions for high-end and high-performance vehicles.

It is possible to benefit simultaneously from the high mechanical outputof a robotic manual transmission and a rapid transition of transmissionratios by interlocking two transmissions in one another in the samecasing. According to this configuration, the first transmission includesthe even ratios, while the second includes the odd ratios. Theseso-called “dual-clutch transmissions” provide excellent transmissioncontinuity of the power during gear shifting, since the ratio thatfollows the current ratio is pre-engaged. Thus, shifting up or downalternately calls on the clutch corresponding to the first transmission,then that corresponding to the second transmission, the two clutchesnever being engaged at the same time. However, dual-clutch transmissionsremain heavier, more expensive and bulkier than traditional manualtransmissions.

A large portion of the worldwide automobile market is equipped withso-called “automatic transmissions”. These transmissions, primarilymarketed in North America, are generally connected to the heat engineusing a hydraulic coupler or a hyperkinetic converter also called“torque converter”. As an alternative to the torque converter, saidtransmissions may be connected to the heat engine using a traditionalautomated dry or oil bath clutch. The automatic transmissions integratea series of planetary gearsets whereof the rotation of the rings can beblocked by brakes, said rings thus blocked then transmitting the torqueproduced by the heat engine to the wheels of the vehicle. Automatictransmissions have the advantage of excellent progressivity in thetransition of the ratios and good continuity of the power transmission.However, their output remains mediocre, since they involve considerableenergy losses, whether due to the torque converter, any “lock-up”clutch, ratio selection clutches, and the various pump(s) and actuatorsthat they include.

Another family of transmissions is called “continuously variabletransmissions” (CVT). Continuously variable transmissions offer infiniteratios between two extreme ratios and generally transmit the workproduced by the heat engine to the wheels of the vehicle via thefriction between a trapezoidal belt and conical flank pulleys, or viathe friction between the rollers of different shapes as found in the“toroidal” transmission produced by the company “Torotrak©” or the“Extroid©” transmission produced by the company “Nissan©”. While thesmallest transmission ratio of said transmission is non-zero, it isordinarily necessary to attach a clutch or torque converter to it placedbetween the heat engine and said transmission to start the vehicle.Unless they are extremely, or even excessively expensive to produce,continuously variable transmissions generally have a lower mechanicaloutput than that of manual transmissions with involute gear pairs.However, said transmissions offering complete transmission continuityand infinite transmission ratios, they allow the heat engine to operateas close as possible to its optimal output in an ordinary drivingsituation of the vehicle, or at its maximum peak power when the driverpushes the vehicle to obtain a maximal acceleration or speed.

Hydraulic continuously variable transmissions also exist comprising atleast one transmitting variable displacement or fixed displacementhydraulic pump and at least one receiving variable displacement or fixeddisplacement hydraulic motor-pump, the transmitting pump or at least theor said motor-pumps having to be with variable displacement. Thetransmitting pumps and/or receiving motor-pumps used are generally basedon axial pistons or on an internal or external gear pair system.

The ratio between the displacement of the transmitting pump and that ofthe receiving hydraulic motor-pump defines the transmission ratio,corrected for the volumetric efficiency of those two members. Hydrauliccontinuously variable transmissions offer infinite transmission ratiosstarting from a zero ratio if the smallest displacement offered by thetransmitting pump is zero. In that case, no clutch or torque converteris necessary. Furthermore, it is possible to provide several receivinghydraulic motor-pumps for a same transmitting hydraulic pump. However,hydraulic continuously variable transmissions accommodate high speeds ofrevolution poorly and have the drawback of having a low average output,said output varying greatly based on the speed and torque to betransmitted. For that reason, hydraulic continuously variabletransmissions are generally provided on slow vehicles such asconstruction vehicles and agricultural machines, since they are compactand flexible, the transmitting pump and the receiving hydraulic motor(s)being able to be connected to each other by rigid or flexible ducts.

Whatever the type, the transmissions may optionally cooperate with oneor more secondary energy storage means, i.e., energy previouslyconverted into mechanical work by the heat engine of the vehicle. Saidstorage means make it possible on the one hand to operate said engine asclose as possible to its optimal output, and on the other hand torecover part of the kinetic energy from the vehicle during itsdeceleration or braking, or part of the gravitational energy accumulatedby said vehicle when it goes down a slope. Once stored, said secondaryenergy may be used later to reaccelerate said vehicle or to maintain itsspeed when it is in motion irrespective of the profile of the path onwhich it travels. Said secondary energy storage means may in particularconsist of an electrochemical or electrostatic electricity storagedevice, the latter then being reusable by an electric engine, a flywheelstoring the kinetic energy recoverable via a mechanical transmission orvia an electrical generator powering the electric engine, or a fluid orpressurized gas reservoir that can be used to drive a receivinghydraulic or pneumatic motor.

The energy capacity, output, power, and number of storage-recoverycycles that the different secondary energy storage means allow overtheir lifetime are the main characteristics that determine theirrelevance and interest. Furthermore, the durability of the storageoffered by said means makes the latter more or less effective inreducing the energy consumption of motor vehicles based on the frequencyand type of journeys they perform. The cost per kilowatt hour of storedenergy and/or per kilowatt of power and the mass and volume energydensity of said secondary energy storage means also make them more orless suitable for motor vehicle propulsion, which calls for widespreadmarketing of said storage means to significantly reduce their carbondioxide emissions worldwide.

The secondary energy storage form most commonly used is electricity.This storage is used on vehicles called “heat-electric hybrids”, whetherthe latter are of the serial or parallel type, and irrespective ofwhether they are rechargeable. Electricity has the advantage ofrelatively high output over its entire production, storage and releasechain, whether it involves the generator that produces said electricityfrom the mechanical work delivered by the heat engine or from thedeceleration of the vehicle, the accumulators that store it, or theelectric motor that converts it back into mechanical work. Theelectrochemical storage devices ordinarily used in this context caneasily store the energy necessary for the vehicle to travel severalkilometers, or even several tens of kilometers.

Used as secondary energy storage means, electricity nevertheless posesvarious problems, including the limited charge power of theelectrochemical storage devices. The latter in fact only make itpossible to store a limited fraction of the vehicle's kinetic energyduring braking thereof, particularly regarding braking with a highdeceleration. Another problem is that the lifetime of the storagedevices is reduced to a limited number of charge-discharge cycles,whereas a very large number of braking operations are done over thelifetime of the motor vehicle. These two problems may be resolvedthrough the use of electrostatic storage devices—also called “supercapacitors”—but the latter are too expensive for wide scale use in theautomotive field. Although they are more affordable, electrochemicalstorage devices nevertheless also remain expensive and require rarematerials, while their manufacturing and recycling potentially posevarious environmental problems. Furthermore, the higher the output ofthe electrical components of the propulsion system of a heat-electrichybrid motor vehicle is, the higher the cost to manufacture saidcomponents will be.

The use of a flywheel to store the secondary energy is known under theacronym “KERS” (Kinetic Energy Recovery System). These devices,primarily used in Formula 1, are made up of a flywheel rotating at ahigh speed in a casing brought to a very low pressure, close to avacuum. Said flywheel may temporarily be mechanically connected to thetransmission of the vehicle using a continuously variable transmission,or indirectly using a generator and an electric motor. KERS have theadvantage of a high energy storage and recovery power, but on the otherhand are expensive and potentially dangerous, generate unwantedgyroscopic effects, and only store the energy for a limited amount oftime.

Secondary energy is stored using at least one pressure accumulator byvarious companies such as “Artemis Intelligent Power®”, “INNAS®”, “BoschRexroth©” and “Eaton®”, known for its “HLA®” (Hydraulic Launch Assist™)launch assist system, the latter two companies focusing particularly onapplications for heavy vehicles or construction vehicles. The vehiclesthus equipped are generally referred to as “hydraulic hybrids”, whetherthey are of the serial or parallel type. Upon request, the pressureaccumulator used is connected either to a transmitting hydraulicmotor-pump when the system is operating in storage mode, or to at leastone receiving hydraulic motor-pump in recovery mode. Secondary energystorage using a pressure accumulator is difficult to apply to motorvehicles due to the high speeds of rotation of the heat engines used inthose vehicles, said speeds being difficult to reconcile with the axialpiston or radial piston hydraulic motor-pumps according to the state ofthe art, which are only capable of the necessary pressure and energyperformance levels. Furthermore, the operating pressure of saidmotor-pumps remains relatively low, below 500 bar, which requires heavyand bulky pressure accumulators to store the secondary energy necessaryfor energy optimization of the vehicle, such accumulators beingdifficult to house in a private passenger vehicle.

In theory, however, the greatest reduction in fuel consumption is foundthrough hydraulic hybridization due to its power, longevity and highstorage-recovery output. In practice, when they are used to transmitmechanical work, hydraulic motor-pumps have a low output compared tothat of involute gear pairs. Thus, the most common configuration is theparallel hydraulic hybrid, which comprises at least one hydraulic pump,a hydraulic motor-pump and hydraulic storage-recovery means alongside aconventional gear transmission. This type of configuration is generallyfound on heavy trucks operating at low speeds and making frequent stopsand starts, such as garbage trucks and urban delivery trucks. However,it should be noted that the company “Peugeot-Citroën” has introduced aprototype thermal-hydraulic hybrid vehicle called “Hybrid Air” and basedon the same architecture, i.e., with the parallel assembly of anautomatic transmission and hydraulic braking energy storage-recoverypumps. The storage pressures remaining relatively low, the accumulatorsremain bulky and take up a large portion of the body understructure ofthe vehicle while only storing a very small quantity of energy. Despitethis, the “Hybrid Air” concept has allowed “Peugeot-Citroën” to announcemuch lower fuel consumption levels compared to the state of the art.

In these fields of application, although internal or external gear pumpsor vane pumps in particular exist, axial and radial piston hydraulicpumps offer the best output. Furthermore, it is possible to vary thedisplacement of these piston pumps, for example using a plate that maybe more or less inclined, or a cage that may be more or lessoff-centered. To accommodate the continuously varying usage conditionsof motor vehicles, said pumps must be able to operate under continuouslyvariable speed, pressure and displacement conditions while preserving ahigh output which, in the current state of the state of the art, is notpossible. In fact, according to the current state of the art, hydraulicpiston pumps have an optimal output for a given speed, pressure anddisplacement. When one strays from these optimal operating conditions,the output of said pumps decreases rapidly, to the point that in thecontext of an automobile application, the benefit of the continuous gearratio variation and of the recovery of the kinetic and gravitationalenergy of the vehicle is low or even zero, and even possibly negative.

The output of the hydraulic pumps is in particular determined by theirsealing, which, being imperfect, implies the existence of leaks, forexample at the pistons and the spool valve of said pumps. The output ofthe hydraulic pumps is also reduced on the one hand by the frictionoccurring in the contact zones between the moving parts and/or betweenthe moving parts and the stationary parts making up said pumps, and onthe other hand by the pressure losses occurring in the ducts of saidpumps.

The use of hydraulic pumps suffers from various pitfalls andcontradictions. A high pressure is favorable for the output of thehydraulic pumps, since it reduces the pressure losses thereof for a sameduct definition. However, said high pressure reduces the volumetricefficiency of said pumps because not only are the leak flow rates of thelatter increased for a same level of sealing, but said flow rates arehigher relative to the flow rate of said pumps. Likewise, atisopressure, the more the displacement of a hydraulic pump is reduced tomeet the instantaneous usage needs of a transmission, the greater itsfriction losses and sealing losses become relative to the work capacitytransmitted by said pump.

However, producing a hydraulic transmission with secondary energystorage intended for automobiles encourages high pressures to favor thefinal output of said transmission as much as possible on the one hand,and to minimize the size of the secondary energy storage members on theother hand, whereas it is imperative in that context to have a hydraulicpump delivering a high output with low displacement, the vehicles mostoften being used at low speeds and low powers.

Furthermore, it will be noted that the need for high outputs remains,due in particular to the issues of controllability of the displacementof the various pumps and/or hydraulic motor-pumps used; issues ofcontinuity of the power transmission, which must not be affected by thepulsations from the transmitting hydraulic pumps and the receivinghydraulic motor-pump(s); and the acoustic and cavitation erosion issues,the high operational pressures causing strong mechanical biases andpotentially violent expansions of hydraulic fluid.

That is why it has been noted that hydraulic piston pumps have beensubject to many developments to improve the functional and energyperformance thereof. One of the most relevant embodiments is that by thecompany “Artemis Intelligent Power©”, which has produced a piston pumphaving excellent sealing levels and low friction losses due to rapidsolenoid valves that regulate the hydraulic fluid intakes-outputs andthe effective capacity of several pump cylinders placed radially arounda cam ring. These solenoid valves and the electronic elements thatcontrol them make up the “Digital Displacement©” concept, whichadvantageously replaces the typical mechanical spool valves, whichgenerate non-negligible leaks and significant friction losses.Furthermore, the hydraulic pump by “Artemis Intelligent Power©”considerably limits the radial forces to which its pistons aresubjected, which limits the associated energy losses thereof in the sameproportions, said pistons operating in cylinders articulated inspherical chambers that cover the end thereof.

However, the pump by “Artemis Intelligent Power©” offers an even morepulsed operation when the displacement of said pump is low, thereduction of said displacement being done by truncating the workingtravel of the pistons. This is even more sensitive given that—for costand bulk reasons—said pump can only include a limited number ofcylinders, in particular in the context of a transmission for motorvehicle use. Whichever hypothesis is selected, the hydraulic pump by“Artemis Intelligent Power©” remains relatively expensive tomanufacture, and the reliability and electricity consumption of itsinput/output solenoid valves biased upon each revolution remain crucialpoints.

Similarly, the company “INNAS©” has developed its “Floating Cup”concept, which results in a variable displacement piston pump with ahigh peak output and generating low pulses. This pump is in particularprovided to propel a motor vehicle according to the “Hybrid” hydraulichybridization concept claimed by that company. Although effective undercertain usage conditions, the “Floating Cup” pump has many leakpassages, and its volumetric efficiency is greatly decreased as aresult, particularly with partial displacements. This is incontradiction with the specifications of a hydraulic pump intended topropel a motor vehicle.

Despite the issues described above and the challenges related to thoseissues, it would be a decisive advantage to have a fixed or variabledisplacement hydraulic motor-pump inexpensive enough to manufacture andwith a high enough energy output for all industrial, household orautomotive applications. Such a motor-pump would in particular make itpossible to produce continuously variable hydraulic transmissions withbraking energy recovery that are efficient, compact and cost-effectiveenough to be applicable to motor vehicles. Aside from being used totransmit the work produced by reciprocating internal combustion engines,such transmissions would make it possible to use non-reciprocating heatengines such as turbine engines, the latter requiring great flexibilityin adjusting the instantaneous transmission ratio, power assistance uponstarting the vehicle to offset the response time of said turbineengines, and recovery of the rotational kinetic energy of the turbinesmaking up said turbine engines when they slow down or stop rotating.

In order to resolve the various problems related to hydraulic pumps andmotors in general, and to manual or automated transmissions, automatictransmissions or continuously variable transmissions, irrespective ofwhether those transmissions are coupled to an electric, inertial orpressure accumulator secondary energy storage device, the fixed orvariable displacement hydraulic motor-pump according to the inventionoffers, depending on the selected embodiment:

-   -   Compatibility with very high operating pressures, possibly up to        two thousand bar or more, with low viscosity hydraulic fluids;    -   Complete reversibility, making it possible to use said hydraulic        motor-pump indifferently as a hydraulic pump and as a hydraulic        motor, with a similar output in “pump” mode and “motor” mode;    -   A high-output mechanical configuration in particular with        hydraulic pistons that are not subject to any radial force, and        with reaction of the majority of the forces by link bearings;    -   An input/output spool valve having low hydraulic leaks and        friction losses;    -   Good continuous controllability of the displacement of said        hydraulic motor-pump from a zero displacement to a maximal        displacement;    -   Relative ease of providing a large number of pistons distributed        angularly so as to limit the pressure and flow rate variations        at the input or output of said hydraulic motor-pump;    -   Good compatibility with the relatively high speeds of rotation        of automobile heat engines;    -   A moderate cost.

In the specific context of the motor vehicle transmission, the fixed orvariable displacement hydraulic motor-pump according to the inventionprovides:

-   -   A high hydraulic transmission output, close to that of manual        transmissions with involute gear pairs, over an expanded speed        and load range and compatible with all uses of a motor vehicle;    -   Vehicle takeoff from a stop without a clutch or torque        converter, those two devices dissipating energy, with the        possibility of a zero transmission ratio followed by infinite        transmission ratios from that zero ratio up to a maximum        transmission ratio;    -   A compact, powerful, robust, high-output secondary energy        storage system, offering a number of storage-recovery cycles        compatible with the entire lifetime of a motor vehicle, and        capable of preserving a large majority of said secondary energy        over long periods of time when said vehicle is stopped.

As a result of these first features, the fixed or variable displacementhydraulic motor-pump according to the invention in particular makes itpossible to:

-   -   Cause the heat engines, and in particular those used to propel        motor vehicles, to work as close as possible to their best        output, by continuously adapting the transmission ratio between        said engines and the wheels of said automobiles;    -   Store all or part of the mechanical work produced by the heat        engines that are used to propel the motor vehicles when said        engines offer a high output, to then restore said work under        driving conditions of said motor vehicles where it is preferable        to avoid using said engines due to their excessively low output,        said storage and release being done at a high output;    -   Recover a significant part of the kinetic energy of the motor        vehicles during braking or deceleration thereof, and/or the        gravitational energy of said vehicles when they descend slopes,        then to release said energy in the form of mechanical work        during the reacceleration of said vehicles, to propel said        vehicles.

Aside from these advantages, the fixed or variable displacementhydraulic motor-pump according to the invention provides, according tovarious embodiments, for:

-   -   Being able to load the reciprocating heat engines artificially        upon cold engine start, i.e., to ask said engines for more power        than necessary to propel the vehicle, that excess power on the        one hand causing increased heat production at the exhaust of        said engines, which accelerates the temperature increase of        their pollutant post-treatment device, and on the other hand        being converted into heat inside said engines to accelerate the        temperature increase of the latter;    -   Performing the “stop and start” function, which provides for        stopping the heat engines of motor vehicles when said vehicles        are stopped, while offering a particularly rapid and powerful        restart of said engines favoring the longevity of their        hydrodynamic bearings, said “stop and start” function        not—according to the invention—causing significant voltage drops        in the power supply of said vehicles;    -   Propelling motor vehicles over distances of several meters or        tens of meters without using their heat engine when the latter        has been stopped using the “stop and start” function, this        particularity reducing the number of restarts of said engine;    -   Assisting heat engines during motor vehicle takeoff from a stop,        so as to offset the possible lack of torque of said engines due        to their low displacement and/or high response time for their        supercharging;    -   Facilitating the reduction of the displacement of motor vehicle        heat engines—strategy intended to reduce the fuel consumption of        said vehicles known by those skilled in the art under the term        “downsizing”—in particular by simplifying the adaptation of        supercharging of said engines, irrespective of whether that        supercharging consists of one or more turbocharger(s) and/or        mechanical compressor(s);    -   Assisting the heat engines during high power demands from the        vehicles, so as to improve the performance of said vehicles;    -   Rotating one or more accessories installed on board motor        vehicles, such as an air conditioning compressor, alternator,        mechanical supercharging compressor, pump or any other member        consuming mechanical work, with the heat engine running or        stopped;    -   Filtering the torque variations at the output of the crankshaft        of reciprocating internal combustion engines so as to reduce the        sound and vibrational annoyances generated by said variations;    -   Assisting the rotation of the shaft connecting the turbine to        the compressor of the turbocharger of the reciprocating internal        combustion engines so as to accelerate the speed increase of        said turbocharger in order to reduce the response time thereof;    -   Limiting the consequences of the response time of supercharging        by the turbocharger of reciprocating internal combustion        engines, by assisting the latter to propel vehicles when said        supercharging does not allow said engines to deliver the desired        torque in a short enough time, and by allowing said engines to        increase their speed quickly to deliver the requested power and        launch the turbine of said turbocharger.

Thus, the fixed or variable displacement hydraulic motor-pump accordingto the invention makes it possible to:

-   -   Greatly reduce fuel consumption and polluting emissions from        motor vehicles, particularly when they are used in urban        settings, in particular by:        -   Running their heat engines as close as possible to their            best energy output or maximum power, irrespective of the            driving conditions;        -   Accelerating heating upon cold start of their heat engine            and their two-way or three-way catalytic converter so as on            the one hand to reduce internal friction losses in the            engine through rapid reduction of the viscosity of their            lubricating oil, and on the other hand reduce the priming            time for said catalytic converter;        -   Allowing, if necessary, regeneration of the particle filter            under all circumstances and/or improving the operation of            their selective catalytic reduction systems with the urea of            nitrogen oxides, these devices most often being provided to            control pollution from the exhaust gases of diesel engine            vehicles;    -   Increase the acceleration performance of motor vehicles without        changing the heat engine or the mass or resistance to forward        motion characteristics thereof, by allowing said engine—during        said acceleration—to operate continuously at maximum power on        the one hand, and not to undergo the transmission        discontinuities specific to the manual or automatic        transmissions on the other hand;    -   Make reducing the weight of motor vehicles less essential to        increase the performance and/or reduce the fuel consumption        thereof, the effect of said weight on said performance and        consumption being lessened by the recovery of kinetic and        gravitational energy and the possibility of running the heat        engines at their optimal output or power, this making it        possible—with equal dynamic and energy performance levels—to        increase the level of comfort and safety equipment and/or reduce        the price of the motor vehicles;    -   Increase the comfort of motor vehicle passengers by accelerating        heating of the passenger compartment of said vehicles while        making it possible to eliminate secondary heating devices for        the passenger compartment as sometimes provided in diesel        vehicles;    -   Greatly decrease the use of conventional motor vehicle friction        brakes, which reduces the wear thereof as well as maintenance        operations, with the corresponding reduction in maintenance        costs and the particulate pollution created by said brakes;    -   Eliminate the additional electrical power necessary for the        “stop & start” function ordinarily entrusted to an electric        starter;    -   Replace the differential axle assembly of motor vehicles with        means allowing dynamic control of the torque applied to each of        the drive wheels of said vehicles.

The fixed or variable displacement hydraulic motor-pump according to theinvention further makes it possible, according to various embodiments,to:

-   -   Offer the drivers of any motor vehicle the choice between        different control modes for the transmission of said vehicle, in        particular to reproduce the driving conditions specific to the        manual or automated, dual-clutch automatic, torque converter        automatic, or continuously variable automatic transmissions,        said drivers having infinite behaviors and steppings of the        transmission ratios, preprogrammed or programmable, and able to        be combined via any man-machine interfaces known by those        skilled in the art, and said fixed or variable displacement        hydraulic motor-pump according to the invention being        controllable using any means—lever, vane, button or pedal—fixed        or pluggable, interchangeable or retractable;    -   Give any motor vehicle an increased motor brake that can be        adjusted to the liking of the driver so as to improve the        driving comfort for said driver and save the brakes of the        vehicle while reducing the risks of overheating of said brakes,        so as to improve driver and passenger safety;    -   Impart a more dynamic nature to the heat engines by assisting        them during their speed increases and braking them during their        speed decreases.

Furthermore, the fixed or variable displacement hydraulic motor-pumpaccording to the invention allows the use of one or more turbines topropel the motor vehicles as an alternative to the reciprocatinginternal combustion engine, particularly according to the configurationdescribed in French patent application no. FR 12 59827 dated Oct. 15,2012 and belonging to the applicant. This combination of means isexpected to drastically reduce the fuel consumption of motor vehiclesand the carbon dioxide emissions resulting therefrom, which are lowrelative to the best references in this field. This combination is alsoexpected to reduce the polluting, acoustic and vibratory emissions ofsaid vehicles under particularly favorable economic conditions.

It is understood that aside from its application to motor vehicletransmission systems, the fixed or variable displacement hydraulicmotor-pump according to the invention may be applied to many industrialand/or household fields.

The other features of the present invention have been described in thedescription and the secondary claims that depend directly or indirectlyon the primary claim.

The fixed or variable displacement hydraulic motor-pump according to thepresent invention comprises:

-   -   At least one motor-pump central rotor that includes a central        rotor power take-off and that is housed on or in a motor-pump        frame, said rotor being able to rotate in at least one central        rotor bearing comprised by said frame while remaining in as        sealed contact as possible with at least one input/output spool        valve kept approximately stationary relative to said frame, said        spool valve being able to connect at least one hydraulic        cylinder arranged radially or tangentially in said rotor with at        least one internal input/output duct and at least one external        input/output duct via an internal input/output central rotor        channel and an input/output central rotor orifice arranged in        the motor-pump central rotor, respectively, one of the ends of        said ducts being secured directly or indirectly and sealably in        the motor-pump frame, while the other end of said ducts is        sealably secured in the input/output spool valve;    -   At least one hydraulic piston able to move in translation in the        hydraulic cylinder and able to push a guided hydraulic piston        plunger or able to be pushed by the latter, said plunger being        guided in translation by a plunger guide arranged radially or        tangentially in the motor-pump central rotor;    -   At least one tangential arm whereof one end is articulated in        the motor-pump central rotor while the other end includes a        tangential arm bearing face on plunger that can exert a force on        a plunger path of contact on tangential arm included by the        guided hydraulic piston plunger, the direction of said force        being approximately tangential to the axis of rotation of said        arm;    -   At least one motor-pump peripheral rotor made up of at least one        cylindrical peripheral rotor casing whereof at least one end        ends with a peripheral rotor flange, said peripheral rotor being        able to rotate in at least one peripheral rotor bearing        supported by a peripheral rotor stator that is directly or        indirectly secured to the motor-pump frame, the motor-pump        central rotor being completely or partially housed inside said        peripheral rotor;    -   At least anti-friction means included by the tangential arm on        its face situated opposite the tangential arm bearing face on        plunger, said means bearing on the inner surface of the        cylindrical peripheral rotor casing.

The fixed or variable displacement hydraulic motor-pump according to thepresent invention comprises a motor-pump peripheral rotor that is forcedto rotate at the same speed as the motor-pump central rotor by anangular peripheral rotor synchro ring secured in rotation to a centralrotor angular synchro ring included by the motor-pump central rotor byat least one angular synchronizing pinion rotating around at least oneangular synchronizing pinion shaft comprised by the motor-pump frame.

The fixed or variable displacement hydraulic motor-pump according to thepresent invention comprises antifriction means that are made up of atleast one tangential arm antifriction roller that can roll on the onehand on a tangential arm rolling track included by the tangential arm onits face situated opposite the tangential arm bearing face on plunger,and on the other hand on a peripheral rotor rolling track included bythe inner surface of the peripheral rotor cylindrical casing, the travelof said roller being limited simultaneously relative to the tangentialarm rolling track and the peripheral rotor rolling track by at least onetangential arm roller rack included by the tangential arm rolling trackand by at least one peripheral rotor roller ring included by theperipheral roller rolling track, said rack and said ring simultaneouslycooperating with at least one roller pinion included by said roller.

The fixed or variable displacement hydraulic motor-pump according to thepresent invention comprises antifriction means made up of at least onetangential arm friction pad included by the tangential arm on its facesituated opposite the tangential arm bearing face on plunger, said padbeing able to come into contact with a peripheral rotor friction trackincluded by the inner surface of the peripheral rotor cylindricalcasing.

The fixed or variable displacement hydraulic motor-pump according to thepresent invention comprises a hydraulic piston that comprises a plungerball joint on hydraulic piston on its circular face that is furthestfrom the motor-pump central rotor, said ball joint being made up of ahollow or raised truncated sphere shape that cooperates with a hydraulicpiston ball joint on plunger comprised by the hydraulic piston guidedplunger, said ball joint also being made up of a hollow or raisedtruncated sphere shape, while the two truncated sphere shapes arecomplementary and constitute a ball joint connection between said pistonand said plunger.

The fixed or variable displacement hydraulic motor-pump according to thepresent invention comprises a hydraulic piston guided plunger thatcomprises a brace placed in the extension of the hydraulic piston, and astrut mounted secured to said brace and perpendicular to the latter,said strut bearing the plunger path of contact on tangential arm, whileeach of its two ends can slide in the plunger guide.

The fixed or variable displacement hydraulic motor-pump according to thepresent invention comprises a motor-pump central rotor that includes acylindrical axle housing in which a tangential arm axle is housedwhereas the tangential arm is passed through by said axle so as to bearticulated in the motor-pump central rotor.

The fixed or variable displacement hydraulic motor-pump according to thepresent invention comprises a motor-pump central rotor that includes atangential arm return spring that bears on the one hand on said rotorand on the other hand on the tangential arm.

The fixed or variable displacement hydraulic motor-pump according to thepresent invention comprises a peripheral rotor rolling track thatincludes at least one hollow or protruding guide rail that cooperateswith at least one hollow or protruding guide groove included by thetangential arm antifriction roller.

The fixed or variable displacement hydraulic motor-pump according to thepresent invention comprises a central rotor bearing that comprises aninner central rotor bearing track provided with at least one centralrotor inner bearing ring, said track being secured to the motor-pumpcentral rotor, on the one hand, and an outer central rotor bearing trackprovided with at least one central rotor outer bearing ring, said trackbeing secured to the motor-pump frame, on the other hand, whereas atleast three central rotor bearing rollers can simultaneously roll on thecentral rotor inner bearing track and on the central rotor outer bearingtrack and remain at a constant distance from each other owing to atleast one roller pinion included by each central rotor bearing rollerand which cooperates with said inner and outer rings.

The fixed or variable displacement hydraulic motor-pump according to thepresent invention comprises a central rotor inner bearing track and/or acentral rotor outer bearing track that includes at least one hollow orprotruding guide rail that cooperates with at least one hollow orprotruding guide groove included by the central rotor bearing rollers.

The fixed or variable displacement hydraulic motor-pump according to thepresent invention comprises a peripheral rotor bearing that comprises aperipheral rotor inner bearing track provided with at least oneperipheral rotor inner bearing ring, said track being secured to themotor-pump peripheral rotor, on the one hand, and a peripheral rotorouter bearing track provided with at least one peripheral rotor outerbearing ring, said track being secured to the peripheral rotor stator,on the other hand, whereas at least three peripheral rotor bearingrollers can roll simultaneously on the peripheral rotor inner bearingtrack and the peripheral rotor outer bearing track and remain at aconstant distance from each other owing to at least one roller pinionincluded by each peripheral rotor bearing roller and which cooperateswith said inner and outer rings.

The fixed or variable displacement hydraulic motor-pump according to thepresent invention comprises a peripheral rotor inner bearing trackand/or a peripheral rotor outer bearing track that includes at least onehollow or protruding guide rail that cooperates with at least one hollowprotruding guide groove included by the peripheral rotor bearingrollers.

The fixed or variable displacement hydraulic motor-pump according to thepresent invention comprises an input/output spool valve that isprevented from rotating with the motor-pump central rotor and is kept inrotation relative to the motor-pump frame by at least one lug or tie roddirectly or indirectly fastened to the motor-pump frame.

The fixed or variable displacement hydraulic motor-pump according to thepresent invention comprises an input/output spool valve that is acylindrical stator housed with slight play in a stator cylinder arrangedat the center of the motor-pump central rotor and coaxially to thelatter, said stator containing an inner duct chamber that communicateson the one hand with the inner input/output duct, and on the other handwith an inner duct angular input/output manifold included by said statorin its periphery via an inner input/output spool valve channel, whereassaid stator also contains an outer duct chamber that communicates on theone hand with the outer input/output duct, and on the other hand with anouter duct angular input/output manifold also included by said stator inits periphery via another inner input/output spool valve channel.

The fixed or variable displacement hydraulic motor-pump according to thepresent invention comprises a cylindrical stator that includes, next tothe inner duct input/output angular manifold, at least one outer ductradial force equalizing groove that communicates with the outer ductchamber via a spool valve equalizing inner channel whereas said statoralso includes at least one inner duct radial force equalizing groovethat communicates with the inner duct chamber via another spool valveequalizing inner channel, said groove being situated next to the outerduct angular input/output manifold.

The fixed or variable displacement hydraulic motor-pump according to thepresent invention comprises a cylindrical stator that includes an axialsealing groove near at least one of its axial ends.

The fixed or variable displacement hydraulic motor-pump according to thepresent invention comprises an input/output spool valve that is an axialstator made up of a distributing flange and an equalizing flange placedaxially on either side of the motor-pump central rotor respectivelyacross from a distribution face and an equalizing face formed on saidrotor, said flanges being mechanically connected to each other via acentral axial stator hub that axially passes through said central rotorvia a stator cylinder arranged at the center of said central rotor andcoaxially thereto, said stator containing an inner duct chamber thatcommunicates on the one hand with the inner input/output duct, and onthe other hand with an inner duct input/output angular manifold axiallyarranged on the inner face of the distributing flange via an inner spoolvalve input/output channel, whereas said stator also contains an outerduct chamber that communicates on the one hand with the outerinput/output duct, and on the other hand with an outer duct input/outputangular manifold also arranged axially on the inner face of thedistributing flange via another inner spool valve input/output channel.

The fixed or variable displacement hydraulic motor-pump according to thepresent invention comprises an inner duct chamber that communicates withan inner duct axial force equalizing groove arranged axially on theinner face of the equalizing flange via a spool valve equalizing innerchannel, whereas the outer duct chamber communicates with an outer ductaxial force equalizing groove also arranged axially on the inner face ofthe equalizing flange via another inner spool valve equalizing channel.

The fixed or variable displacement hydraulic motor-pump according to thepresent invention comprises a distributing flange and/or an equalizingflange that includes a radial sealing groove at least at one of itsradial ends.

The fixed or variable displacement hydraulic motor-pump according to thepresent invention comprises an axial stator central hub that includes anaxial sealing groove at least at one of its axial ends or at any pointalong its length.

The fixed or variable displacement hydraulic motor-pump according to thepresent invention comprises all or part of the inner duct input/outputangular manifold, the outer duct input/output angular manifold, theouter duct radial force equalizing groove, the inner duct radial forceequalizing groove, the axial sealing groove, the inner duct axial forceequalizing groove, the outer duct axial force equalizing groove or theradial sealing groove, which is provided with a spool valve groovesegment.

The fixed or variable displacement hydraulic motor-pump according to thepresent invention comprises a spool valve groove segment that has atleast one flank segment that laterally establishes sealing with thecylindrical stator or the axial stator, and at least one segment sealingline which on the one hand comes into contact with the motor-pumpcentral rotor to form sealing, and which on the other hand is subjectedto a force that tends to press it on said rotor due to the thrustexerted by a pressurized motor-pump oil contained by the cylindricalstator or the axial stator on the spool valve groove segment, said forcebeing limited due to a small sprayed surface subjected to the pressureof said oil offered by said segment, which results from a segment forcereacting shoulder included by said segment that cooperates with anothershoulder arranged in the cylindrical stator or in the axial stator.

The fixed or variable displacement hydraulic motor-pump according to thepresent invention comprises a spool valve groove segment that is kept incontact with the motor-pump central rotor by a segment groove bottomspring.

The fixed or variable displacement hydraulic motor-pump according to thepresent invention comprises a spool valve groove segment that is made upof two half-segments that each have at least one segment flank kept incontact with the cylindrical stator or with the axial stator by asegment separating spring.

The fixed or variable displacement hydraulic motor-pump according to thepresent invention comprises an inner input/output duct that is securedin the input/output spool valve and/or in the motor-pump frame by one orthe other of the ends of said duct using at least one fixed ductcovering ball joint and/or at least one sliding duct covering balljoint, said ball joint having a covering ball joint step that may reston a covering ball joint seat.

The fixed or variable displacement hydraulic motor-pump according to thepresent invention comprises a fixed duct covering ball joint that iskept in contact with its covering ball joint seat by a covering balljoint spring that bears on the one hand on the input/output spool valveor on the motor-pump frame or on a sliding duct covering ball joint, andon the other hand directly or indirectly on said fixed covering balljoint.

The fixed or variable displacement hydraulic motor-pump according to thepresent invention comprises a sliding duct covering ball joint that ismade up of at least one sliding covering half-ball joint axially passedthrough by the inner input/output duct, said half-ball joint being ableto translate axially and sealably relative to said inner duct, whereassaid half-ball joint is kept in contact with its covering ball jointseat by a covering ball joint spring that bears on the one hand on theinput/output spool valve or on the motor-pump frame or on anothersliding covering half-ball joint, and on the other hand directly orindirectly on said sliding covering half-ball joint.

The fixed or variable displacement hydraulic motor-pump according to thepresent invention comprises an outer input/output duct that is securedin the input/output spool valve and/or in the motor-pump frame by one orthe other of the ends of said duct using at least one fixed ductcovering ball joint, said ball joint having a covering ball joint stepthat can rest on a covering ball joint seat.

The fixed or variable displacement hydraulic motor-pump according to thepresent invention comprises an inner duct chamber that is closed by aninner duct plug.

The fixed or variable displacement hydraulic motor-pump according to thepresent invention comprises an outer duct chamber that is closed by anouter duct plug that is passed through by said outer input/output duct.

The fixed or variable displacement hydraulic motor-pump according to thepresent invention comprises an inner input/output duct that is housedcompletely or partially inside the outer input/output duct.

The fixed or variable displacement hydraulic motor-pump according to thepresent invention comprises a motor-pump frame that comprises aconnecting satellite in which the inner input/output duct and/or theouter input/output duct are secured.

The fixed or variable displacement hydraulic motor-pump according to thepresent invention comprises a peripheral rotor stator that isarticulated on the angular synchronizing pinion axle, around which itcan rotate under the action of a displacement varying servomotor.

The fixed or variable displacement hydraulic motor-pump according to thepresent invention comprises a displacement varying servomotor that is arotary electric servomotor motor that can rotate—in one direction or theother and by means of a servomotor reducing gear—a displacement-varyingring driving pinion, said pinion being able to rotate in a bearingarranged in the motor-pump frame and being able to rotate adisplacement-varying ring secured to the peripheral rotor stator, thepitch circle of said ring being centered on the angular synchronizingpinion axle.

The fixed or variable displacement hydraulic motor-pump according to thepresent invention comprises rephasing means that are inserted betweenthe peripheral rotor angular synchro ring and the central rotor angularsynchro ring.

The fixed or variable displacement hydraulic motor-pump according to thepresent invention comprises rephasing means that are made up of at leastone intermediate rephasing gear pair including at least one rephasingtoothed wheel rotating around at least one rephasing axle secured to theperipheral rotor stator, said gear pair being inserted between theperipheral rotor angular synchro ring and the angular synchronizingpinion.

The fixed or variable displacement hydraulic motor-pump according to thepresent invention comprises an inner input/output duct and an outerinput/output duct that are connected to the input or the output,respectively, of at least one second fixed or variable displacementhydraulic motor-pump, the fixed or variable displacement hydraulicmotor-pump and the second fixed or variable displacement hydraulicmotor-pump together making up a hydraulic transmission device.

The fixed or variable displacement hydraulic motor-pump according to thepresent invention comprises a central rotor power take-off of the fixedor variable displacement motor-pump that is mechanically connected to atleast one drive motor included by a motor vehicle, whereas the secondfixed or variable displacement hydraulic motor-pump is mechanicallyconnected to at least one driving wheel or track included by saidvehicle, or vice versa.

The fixed or variable displacement hydraulic motor-pump according to thepresent invention comprises an inner input/output duct that can beconnected with at least one high-pressure accumulator by at least oneinner duct high-pressure accumulator valve.

The fixed or variable displacement hydraulic motor-pump according to thepresent invention comprises an outer input/output duct that can beconnected with at least one high-pressure accumulator by at least oneouter duct high-pressure accumulator valve.

The fixed or variable displacement hydraulic motor-pump according to thepresent invention comprises an inner input/output duct that can beconnected with at least one low-pressure accumulator by at least oneinner duct low-pressure accumulator valve.

The fixed or variable displacement hydraulic motor-pump according to thepresent invention comprises an outer input/output duct that can beconnected with at least one low-pressure accumulator by at least oneouter duct low-pressure accumulator valve.

The fixed or variable displacement hydraulic motor-pump according to thepresent invention comprises a high-pressure accumulator and/or alow-pressure accumulator that comprises at least one accumulatorseparator piston able to move sealably in a blind accumulator cylinder,said piston delimiting, with said cylinder, a gas compartment containinga pressurized gas and oil compartment containing a motor-pump oil, thelatter compartment being able to be connected with the innerinput/output duct and/or the outer input/output duct.

The fixed or variable displacement hydraulic motor-pump according to thepresent invention comprises an oil compartment that includes anaccumulator-closing gate that the accumulator separator piston can presson an accumulator gate seat by pushing on a high-stiffness resistingspring inserted between said piston and said gate, so as to sealablyisolate said compartment from the inner input/output duct and/or theouter input/output duct, said gate cooperating—unlike the high-stiffnessresisting spring—with a low-stiffness resisting spring that tends toseparate said gate from said seat.

The fixed or variable displacement hydraulic motor-pump according to thepresent invention comprises an accumulator separator piston that canpush on the high-stiffness resisting spring by means of a high-stiffnessspring plunger that is guided in longitudinal translation by a gate andplunger guide secured to the high-pressure accumulator and/or thelow-pressure accumulator, said gate guide also guiding the accumulatorclosing gate and including a plunger stop that determines the maximumtravel of the high-stiffness spring plunger toward the accumulatorseparator piston.

The fixed or variable displacement hydraulic motor-pump according to thepresent invention comprises a gate and plunger guide that includes atleast one radial gate guide orifice that connects the oil compartmentwith the accumulator gate seat so as to allow the motor-pump oil tocirculate between the inner input/output duct and/or the outerinput/output duct and said oil compartment.

The fixed or variable displacement hydraulic motor-pump according to thepresent invention comprises a high-pressure accumulator and/or alow-pressure accumulator that is connected to the inner input/outputduct and/or the outer input/output duct by means of an accumulatorlocking valve that can sealably isolate said accumulator from said innerduct and/or said outer duct.

The fixed or variable displacement hydraulic motor-pump according to thepresent invention comprises a low-pressure accumulator that is suppliedwith a motor-pump oil by at least one low-pressure pump driven by alow-pressure pump motor, the intake duct of said pump being connected toa motor-pump oil reservoir whereas its discharge duct is connected tosaid accumulator.

The fixed or variable displacement hydraulic motor-pump according to thepresent invention comprises an inner input/output duct that can beconnected, by an inner duct exchanger-dissipater valve, with at leastone exchanger-dissipater inner duct included by a pressure lossexchanger-dissipater, said duct comprising at least one outer dissipaterheat exchange surface that is in contact with a coolant gas or a coolantliquid.

The fixed or variable displacement hydraulic motor-pump according to thepresent invention comprises an outer input/output duct that can beconnected, by an outer duct exchanger-dissipater valve, with at leastone inner exchanger-dissipater duct included by a pressure lossexchanger-dissipater, said duct comprising at least one outer dissipaterheat exchange surface that is in contact with a coolant gas or a coolantliquid.

The fixed or variable displacement hydraulic motor-pump according to thepresent invention comprises an inner input/output duct that can beconnected with a secondary hydraulic motor by an inner duct secondarymotor valve.

The fixed or variable displacement hydraulic motor-pump according to thepresent invention comprises an outer input/output duct that can beconnected with a secondary hydraulic motor by an outer duct secondarymotor valve.

The fixed or variable displacement hydraulic motor-pump according to thepresent invention comprises a secondary hydraulic motor that is made upof at least one hydraulic turbine mounted on a hydraulic turbine shaftthat includes at least one hydraulic turbine blade on which at least onehydraulic turbine injector can axially and/or radially spray a jet of amotor-pump oil.

The fixed or variable displacement hydraulic motor-pump according to thepresent invention comprises a motor-pump management computer thatcontrols the displacement-varying servomotor to control the displacementof the fixed or variable displacement hydraulic motor-pump, includingthat making up the hydraulic transmission device, irrespective ofwhether the latter is integrated into the motor vehicle, said computeralso being able to command the inner duct high-pressure accumulatorvalve and/or the outer duct high-pressure accumulator valve and/or theinner duct low-pressure accumulator valve and/or the outer ductlow-pressure accumulator valve and/or the accumulator locking valveand/or the low-pressure pump motor and/or the inner ductexchanger-dissipater valve and/or the outer duct exchanger-dissipatervalve and/or the inner duct secondary motor valve and/or the outer ductsecondary motor valve.

The fixed or variable displacement hydraulic motor-pump according to thepresent invention comprises a motor-pump management computer that isconnected, by wired, lighted or electromagnetic information transmissionmeans, to at least one shifting lever and/or at least one shifting vaneand/or at least one shifting button and/or at least one clutch pedaland/or at least one brake pedal and/or at least one accelerator pedalincluded by a driving station comprised by the motor vehicle.

The fixed or variable displacement hydraulic motor-pump according to thepresent invention comprises a motor-pump management computer that isconnected, by wired, lighted or electromagnetic information transmissionmeans, to at least one transmission configuration button or knob and/ora transmission configuration screen and/or a transmission configurationmicrophone and/or a transmission configuration speaker included by adriving station comprised by said motor vehicle.

The description that follows in light of the appended drawings providedas non-limiting examples make it possible to better understand theinvention, the features thereof, and the advantages it may procure:

FIGS. 1 and 2 are three-dimensional views of the fixed or variabledisplacement hydraulic motor-pump according to the invention, seen fromthe front and the rear, respectively.

FIG. 3 is an exploded view of the fixed or variable displacementhydraulic motor-pump according to the invention.

FIG. 4 is a cutaway view of the fixed or variable displacement hydraulicmotor-pump according to the invention.

FIGS. 5 and 6 are three-dimensional cross-sectional views of the fixedor variable displacement hydraulic motor-pump according to the inventionat zero displacement and maximum displacement, respectively, without themotor-pump frame of the latter.

FIG. 7 is an exploded view of the motor-pump central rotor of the fixedor variable displacement hydraulic motor-pump according to theinvention, and the main components with which it cooperates.

FIG. 8 is an exploded view of the motor-pump peripheral rotor of thefixed or variable displacement hydraulic motor-pump according to theinvention, and the main components with which it cooperates.

FIG. 9 is an exploded view of the bearing of the motor-pump peripheralrotor of the fixed or variable displacement hydraulic motor-pumpaccording to the invention.

FIG. 10 is an exploded view of the input/output spool valve of the fixedor variable displacement hydraulic motor-pump according to theinvention, said spool valve being made up of a cylindrical stator.

FIG. 11 is a cutaway view of the input/output spool valve of the fixedor variable displacement hydraulic motor-pump according to theinvention, said spool valve being made up of a cylindrical stator.

FIGS. 12 and 13 are diagrammatic cross-sectional and three-dimensionalviews, respectively, of the spool valve groove segment of the fixed orvariable displacement hydraulic motor-pump according to the invention.

FIGS. 14 to 17 diagrammatically show the developed surface of thecylindrical stator of the fixed or variable displacement hydraulicmotor-pump according to the invention, said figures being organizedsequentially so as to illustrate the movement and the differentpositions that result therefrom of the central rotor input/outputorifices relative to the inner duct input/output angular manifold andthe outer duct input/output angular manifold included by said surface.

FIGS. 18 and 19 are exploded right lateral and left lateral views,respectively, of the motor-pump central rotor and its central rotorpower takeoff of the fixed or variable displacement hydraulic motor-pumpaccording to the invention, and the input/output spool valve of saidmotor-pump, said spool valve being made up of an axial stator.

FIGS. 20 and 21 are diagrammatic views illustrating the operation of theintermediate re-phasing gear pair inserted between the peripheral rotorangular synchro ring and the angular synchronizing pinion.

FIG. 22 is a diagrammatic cross-section of the fixed or variabledisplacement hydraulic motor-pump according to the invention whereof thetangential arms are provided with a tangential arm friction pad thatcooperates with a peripheral rotor friction track.

FIG. 23 illustrates a block diagram of the fixed or variabledisplacement hydraulic motor-pump according to the inventionproducing—with a second fixed or variable displacement hydraulicmotor-pump—a hydraulic transmission device on the one hand allowing adrive motor to propel a motor vehicle and on the other hand making itpossible to store-recover part of the kinetic and/or gravitationalenergy of said vehicle in a high-pressure accumulator.

FIG. 24 is a diagrammatic cross-section of the high-pressure and/orlow-pressure accumulator included by the hydraulic transmission deviceprovided by the fixed or variable displacement hydraulic motor-pumpaccording to the invention.

FIGS. 25, 26 and 27 are diagrammatic cross-sections that illustrate theoperation of the accumulator closing gate of the high-pressure and/orlow-pressure accumulator included by the hydraulic transmission deviceas provided by the fixed or variable displacement hydraulic motor-pumpaccording to the invention.

FIG. 28 is a diagrammatic view of a motor vehicle equipped on the onehand with a reciprocating internal combustion engine mountedlongitudinally, and on the other hand with a hydraulic transmissiondevice that forms—with a second fixed or variable displacement hydraulicmotor-pump—the fixed or variable displacement hydraulic motor-pumpaccording to the invention, said second motor-pump driving the reardrive wheels of said vehicle via a transmission shaft and a differentialaxle assembly.

FIG. 29 is a diagrammatic view of a motor vehicle equipped on the onehand with a reciprocating internal combustion engine mountedtransversely, and on the other hand with a hydraulic transmission devicethat forms—with two second fixed or variable displacement hydraulicmotor-pumps—the fixed or variable displacement hydraulic motor-pumpaccording to the invention, said second motor-pumps each driving a reardrive wheel of said vehicle.

FIG. 30 is a diagrammatic view of a motor vehicle equipped on the onehand with a reciprocating internal combustion engine mountedtransversely, and on the other hand with a hydraulic transmission devicethat forms—with two second fixed or variable displacement hydraulicmotor-pumps—the fixed or variable displacement hydraulic motor-pumpaccording to the invention, said second motor-pumps each driving a frontdrive wheel of said vehicle.

FIG. 31 is a diagrammatic view of a motor vehicle equipped on the onehand with a low-pressure internal combustion turbine engine according tothe configuration described in French patent application no. FR 12 59827belonging to the applicant, and on the other hand, a hydraulictransmission device that forms—with a second fixed or variabledisplacement hydraulic motor-pump—the fixed or variable displacementhydraulic motor-pump according to the invention, said second motor-pumpdriving the front drive wheels of said vehicle via a reducing gear, adifferential axle assembly, and transmission shafts.

FIG. 32 is a diagrammatic view of a driving station included by a motorvehicle propelled by the hydraulic transmission device as provided bythe fixed or variable displacement hydraulic motor-pump according to theinvention.

FIG. 33 is a diagrammatic cross-sectional view of a secondary hydraulicmotor included by the hydraulic transmission device as provided by thefixed or variable displacement hydraulic motor-pump according to theinvention, said secondary hydraulic motor being formed by a hydraulicturbine.

DESCRIPTION OF THE INVENTION

FIGS. 1 to 33 show the fixed or variable displacement hydraulicmotor-pump 1, various details of its components, its alternatives andits accessories.

The hydraulic motor-pump 1 according to the invention comprises at leastone motor-pump central rotor 3, the details of which are shown in FIG.7, which includes a central rotor power takeoff 4 and which is housed onor in a motor-pump frame 2, said rotor 3 being able to rotate in atleast one central rotor bearing 5 comprised by said frame 2 whileremaining in the most sealed possible contact with at least oneinput/output spool valve 43 kept approximately stationary relative tosaid frame 2, said spool valve 43 being able to connect at least onehydraulic cylinder 14 arranged radially or tangentially in said rotor 3with at least one inner input/output duct 57 and at least one outerinput/output duct 58 via a central rotor input/output inner channel 15and a central rotor input/output orifice 16 formed in the motor-pumpcentral rotor 3, respectively, one of the ends of said ducts 57, 58being directly or indirectly and sealably secured in the motor-pumpframe 2, while the other end of said ducts 57, 58 is sealably secured inthe input/output spool valve 43.

According to the hydraulic motor-pump 1 according to the invention, thecentral rotor bearing 5 may be made up of a hydrodynamic or hydrostaticbearing, a ball or rolling bearing, of any type, a gas or magneticbearing or any other bearing known by those skilled in the art. It willbe noted that the motor-pump frame 2 can serve as a motor-pump casing orcooperate with a motor-pump casing attached on or around said frame 2that protects the main components of the hydraulic motor-pump 1 from theoutside environment, while protecting said environment from sprays inparticular of the motor-pump oil 14 contained in said motor-pump 1.Furthermore, said motor-pump casing may completely or partially form amotor-pump oil reservoir 121 in which at least part of a motor-pump oil114 is stored that the hydraulic motor-pump 1 needs to operate, whilethe various mechanical members of said motor-pump 1 may in particular belubricated by splashing in said oil 114.

It will be noted that, according to one particular embodiment of thehydraulic motor-pump 1 according to the invention, the innerinput/output duct 57 and/or the outer input/output duct 58 may include acheck valve only allowing the motor-pump oil 114 circulating in saidducts 57, 58 to travel in one direction, whereas the latter may—inaddition to or in place of said check valve—comprise a closing valve.Furthermore, the inner input/output duct 57 and/or the outerinput/output duct 58 may include a pulsation dampener for example formedby a low-capacity hydraulic accumulator. The central rotor power takeoff4 may be integral with the motor-pump central rotor 3 or be fastened onthe latter, and may be made up of a tripod or multipod, with a male orfemale splined pin, a Cardan joint, a homokinetic joint, a metal ornon-metal flange, and in general, any coupling device making it possibleto transmit a rotational movement from one part to another.

Furthermore, as shown in FIGS. 4 to 7, the hydraulic motor-pump 1according to the invention comprises at least one hydraulic piston 13capable of translating in the hydraulic cylinder 14 and able to push aguided hydraulic piston plunger 18 or able to be pushed by the latter,the translation of said plunger 18 being guided by a plunger guide 19formed radially or tangentially in the motor-pump central rotor 3, saidhydraulic piston 13 causing—during its back-and-forth movement—amotor-pump oil 114 to circulate between the inner input/output duct 57and the outer input/output duct 58, and in particular being able toinclude, on its periphery, one or more sealing segment(s) of any typeknown by those skilled in the art, and/or patterns causing a pressuredrop.

The hydraulic motor-pump 1 according to the invention also includes atleast one tangential arm 22 particularly shown in FIGS. 4 to 7, one endof which is articulated in the motor-pump central rotor 3 while theother end includes a tangential arm bearing face on plunger 23 that mayexert a force on a plunger on tangential arm path of contact 21 includedby the guided hydraulic piston plunger 18, the direction of said forcebeing approximately tangential to the axis of rotation of said arm 22,the profile of the tangential arm bearing face on plunger 23 and that ofthe plunger on tangential arm path of contact 21 being calculated sothat on the one hand, the Hertz pressure to which those two surfaces incontact 23, 21 are subjected is as low as possible, and on the otherhand so that the relative movement of said face 23 relative to said path21 is as small as possible so as to reduce the friction losses generatedat the contact between said face 23 and said path 21.

The hydraulic motor-pump 1 according to the invention also comprises atleast one motor-pump peripheral rotor 29 as shown in FIG. 8, made up ofat least one peripheral rotor cylindrical casing 32 whereof at least oneend ends with a peripheral rotor flange 35, said peripheral rotor 29rotating in at least one peripheral rotor bearing 36 borne by aperipheral rotor stator 65 that is directly or indirectly secured to themotor-pump frame 2, the motor-pump central rotor 3 being completely orpartially housed inside said peripheral rotor 29.

According to one particular embodiment of the hydraulic motor-pump 1according to the invention, the peripheral rotor flange 35 may either bemade from the same material billet as the peripheral rotor cylindricalcasing 32, or may be fastened to the latter by screwing, welding,crimping, or any other mechanical fastening method known by thoseskilled in the art.

The hydraulic motor-pump 1 according to the invention also comprisesantifriction means 196 included by the tangential arm 22 on the facethereof situated opposite the tangential arm bearing face on plunger 23,said means 196 bearing on the inner surface of the peripheral rotorcylindrical casing 32.

It will be noted in FIGS. 3, 4, 7, 8 and 22 that the hydraulicmotor-pump 1 according to the invention comprises a motor-pumpperipheral rotor 29 that may be forced to rotate at the same speed asthe motor-pump central rotor 3 by an peripheral rotor angular synchroring 42 secured in rotation to a central rotor angular synchro ring 11included by the motor-pump central rotor 3, by at least one angularsynchronizing pinion 12 rotating around at least one angularsynchronizing pinion axle 81 comprised by the motor-pump frame 2.

According to one particular embodiment of the hydraulic motor-pump 1according to the invention, the gear device formed by the peripheralrotor angular synchro ring 42, the central rotor angular synchro ring 11and the angular synchronizing pinion 12 may be replaced by at least onechain, belt, shaft, or any other transmission means known by thoseskilled in the art.

As shown in FIGS. 3 to 7, [in] the hydraulic motor-pump 1 according tothe invention, the anti-friction means 196 are made up of at least onetangential arm antifriction roller 28 that can roll on the one hand on atangential arm rolling track 26 included by the tangential arm 22 on theface thereof situated opposite the tangential arm bearing face onplunger 23, and on the other hand on a peripheral rotor rolling track 33included by the inner surface of the peripheral rotor cylindrical casing32, the movement of said roller 28 simultaneously being limited relativeto the tangential arm rolling track 26 and the peripheral rotor rollingtrack 33 by at least one tangential arm roller rack 27 included by thetangential arm rolling track 26 and by at least one peripheral rotorroller ring 34 included by the peripheral rotor rolling track 33, saidrack 27 and said ring 34 simultaneously cooperating with at least oneroller pinion 87 included by said roller 28.

According to one particular embodiment of the hydraulic motor-pump 1according to the invention, the tangential arm roller rack 27 and theperipheral rotor roller ring 34 can be separated from the rolling tracks26, 33 with which they cooperate so as to allow the manufacture and/orassembly thereof independently, while the peripheral rotor roller ringmay for example be discontinuous such that only the angular sectors ofsaid ring 34 that actually cooperate with the tangential armantifriction roller 28 are provided with teeth.

It will further be noted that the tangential arm rolling track 26 mayinclude at least one hollow or protruding guide rail that cooperateswith at least one hollow or protruding guide groove 86 included by thetangential arm anti-friction roller 28, said rail and said groove 86guaranteeing the axial maintenance in position of said antifrictionroller 28 relative to the hydraulic motor-pump 1 according to theinvention.

It will also be noted that preferably, the rolling diameter of thetangential arm antifriction roller 28 is substantially equal to that ofthe pitch circle of the roller pinion 87, the inside diameter of theperipheral rotor rolling track 33 is substantially equal to that of thepitch circle of the peripheral rotor roller ring 34, while the pitchline of the tangential arm roller rack 27 coincides with the functionalsurface of the tangential arm rolling track 26.

According to one particular embodiment of the hydraulic motor-pump 1according to the invention, the roller pinion 87 may either be made inthe same material billet as the tangential arm antifriction roller 28itself, or attached on the latter by bracing, crimping, welding, or anyother means known by those skilled in the art making it possible tofasten said pinion 87 on said roller 28. It will be noted that thisembodiment of the tangential arm antifriction roller 28 may also applyto a central rotor bearing roller 6 and/or a peripheral rotor bearingroller 37 that may also be included by the hydraulic motor-pump 1.

FIG. 22 illustrates an alternative of the fixed or variable displacementhydraulic motor-pump 1 whereof the antifriction means 196 are formed bytangential arm friction pads 194.

According to this particular alternative of the hydraulic motor-pump 1according to the invention, said motor-pump 1 comprises at least onetangential arm friction pad 194 included by the tangential arm 22 on theface thereof situated opposite the tangential arm bearing face onplunger 23 that may come into contact with a peripheral rotor frictiontrack 195 included by the inner surface of the peripheral rotorcylindrical casing 32.

According to one particular embodiment of the hydraulic motor-pump 1according to the invention, the tangential arm friction pad 194 and/orthe peripheral rotor friction pad 195 may be nitrided, cemented and/orcoated with DLC (Diamond-Like Carbon) or any other hard coating and/orcoating with a low friction coefficient. It will also be noted that thetangential arm friction pad 194 may be an independent piece attached onthe tangential arm 22 by screwing, welding, crimping, or any othermechanical fastening method known by those skilled in the art.

As illustrated in FIG. 7, the fixed or variable displacement hydraulicmotor-pump 1 according to the invention may provide a hydraulic piston13 that comprises a plunger ball joint on hydraulic piston 17 on itscircular face that is furthest from the motor-pump central rotor 3, saidball joint 17 being made up of a hollow or raised truncated sphere shapethat cooperates with a hydraulic piston ball joint on plunger 20comprised by the hydraulic piston guided plunger 18, said ball joint 20also being made up of a hollow or raised truncated sphere shape, whilethe two truncated sphere shapes are complementary and constitute arolling connection between said piston 13 and said plunger 18.

Furthermore, the hydraulic piston guided plunger 18 may comprise a brace82 that is clearly shown in FIG. 7 and that is placed in the extensionof the hydraulic piston 13, and a strut 83 mounted secured to said brace82 and perpendicular to the latter, said strut 83 bearing the plungerpath of contact on tangential arm 21 while each of its two ends canslide in the plunger guide 19. It will be noted that according to oneparticular embodiment of the hydraulic motor-pump 1 according to theinvention, the strut 83 may be pre-stressed so that when the tangentialarm bearing face on plunger 23 exerts its maximum force on the plungerpath of contact on tangential arm 21, the contact pressure between saidface 23 and said path 21 is distributed as uniformly as possible. Itwill further be noted that said face 23 and/or said path 21 may benitrided, cemented and/or coated with DLC (Diamond-Like Carbon), or anyother hard coating and/or coating with a low friction coefficient.

FIG. 7 shows that the motor-pump central rotor 3 includes a cylindricalaxle housing 84 in which a tangential arm axle 24 is housed, while thetangential arm 22 is crossed through by said axle 24 so as to bearticulated in the motor-pump central rotor 3. It will further be notedthat the cylindrical axle housing 84 may either be formed directly inthe material of the motor-pump central rotor 3, or formed in a piecefastened on said rotor 3 by screwing, welding, or any other fasteningmeans known by those skilled in the art.

Consequently, the motor-pump central rotor 3 may include a tangentialarm return spring 25 that bears on the one hand on said rotor 3, and onthe other hand on the tangential arm 22, said spring 25 tending—by theforce that it produces—to separate said arm 22 from said rotor 3 andbeing able to work by compression, traction or torsion and to be of thehelical, blade, or any other type known by those skilled in the art(FIG. 7).

As shown in FIG. 8, the peripheral rotor rolling track 33 may include atleast one hollow or protruding guide rail 85 that cooperates with atleast one hollow or protruding guide groove 86 included by thetangential arm antifriction roller 28, said rail 85 and said groove 86guaranteeing the axial maintenance in position of said antifrictionroller 28 relative to the hydraulic motor-pump 1 according to theinvention.

According to one particular embodiment of the fixed or variabledisplacement hydraulic motor-pump 1 illustrated in FIGS. 1 to 4 and FIG.7, the central rotor bearing 5 may comprise a central rotor bearinginner track 7 provided with at least one central rotor bearing innerring 9, said track 7 being secured to the motor-pump central rotor 3, onthe one hand, and an outer central rotor bearing track 8 provided withat least one central rotor bearing outer ring 10, said track 8 beingsecured to the motor-pump frame 2, on the other hand, while at leastthree central rotor bearing rollers 6 can roll at simultaneously on thecentral rotor bearing inner track 7 and the central rotor bearing outertrack 8 and remain at a constant distance from one another owing to atleast one roller pinion 87 included by each central rotor bearing roller6 and that cooperates with said inner 9 and outer 10 rings.

According to one particular embodiment of the hydraulic motor-pump 1according to the invention, the central rotor bearing inner ring 9 andthe central rotor bearing outer ring 10 can be separated from the inner7 and outer 8 central rotor bearing tracks with which they cooperate soas to allow them to be manufactured and/or assembled independently. Itwill be noted that preferably, the rolling diameter of the central rotorbearing rollers 6 is substantially equal to that of the pitch circle ofthe roller pinion 87 included by each said central rotor bearing roller6, the outer diameter of the central rotor bearing inner track 7 issubstantially equal to that of the pitch circle of the central rotorbearing inner ring 9, while the inner diameter of the central rotorbearing outer track 8 is substantially equal to that of the pitch circleof the central rotor bearing outer ring 10.

Furthermore, the central rotor bearing inner track 7 and/or the centralrotor bearing outer track 8 may include at least one hollow orprotruding guide rail 85 that cooperates with at least one hollow orprotruding guide groove 86 included by the central rotor bearing rollers6, said rail 85 and said groove 86 having complementary shapes andguaranteeing the axial maintenance in position of said bearing rollers 6relative to the hydraulic motor-pump 1 according to the invention,whereas, according to one particular embodiment of said motor-pump 1,the guide rail 85 and/or the guide groove 86 may be separated from theinner 7 and outer 8 central rotor bearing tracks with which theycooperate so as to allow them to be manufactured and/or assembledindependently.

As illustrated in FIG. 9, the peripheral rotor bearing 36 may on the onehand comprise a peripheral rotor bearing inner track 38 provided with atleast one peripheral rotor bearing inner ring 40, said track 38 beingsecured to the motor-pump peripheral rotor 29, and on the other hand, aperipheral rotor bearing outer track 39, provided with at least oneperipheral rotor bearing outer ring 41, said track 39 being secured tothe peripheral rotor stator 65, while at least three peripheral rotorbearing rollers 37 can roll simultaneously on said peripheral rotorbearing inner track 38 and on the peripheral rotor bearing outer track39 and remain at a constant distance from one another owing to at leastone roller pinion 87 included by each peripheral rotor bearing roller 37and which cooperates with said inner 40 and outer 41 rings.

According to one particular embodiment of the hydraulic motor-pump 1according to the invention illustrated in FIG. 9, the peripheral rotorbearing inner ring 40 and the peripheral rotor bearing outer ring 41 maybe separated from the inner 38 and outer 39 peripheral rotor bearingtracks with which they cooperate so as to allow them to be manufacturedand/or assembled independently. It will be noted that preferably, therolling diameter of the peripheral rotor bearing rollers 37 issubstantially equal to that of the pitch circle of the roller pinion 87included by each said peripheral rotor bearing roller 37, the outerdiameter of the peripheral rotor bearing inner track 38 is substantiallyequal to that of the pitch circle of the peripheral rotor bearing innerring 40, while the inner diameter of the peripheral rotor bearing outertrack 39 is substantially equal to that of the pitch circle of theperipheral rotor bearing outer ring 41.

It will be noted that the peripheral rotor bearing inner track 38 and/orthe peripheral rotor bearing outer track 39 may include at least onehollow or protruding guide rail 85 that cooperates with at least onehollow or protruding guide groove 86 included by the peripheral rotorbearing rollers 37, said rail 85 and said groove 86 having acomplementary shape and guaranteeing the maintenance in axial positionof said bearing rollers 37 relative to the hydraulic motor-pump 1according to the invention, whereas, according to one particularembodiment of said motor-pump 1, the guide rail 85 and/or the guidegroove 86 can be separated from the inner 38 and outer 39 peripheralrotor bearing tracks with which they cooperate so as to allow them to bemanufactured and/or assembled independently.

The fixed or variable displacement hydraulic motor-pump 1 according tothe invention may comprise an input/output spool valve 43 that isprevented from rotating with the motor-pump central rotor 3 and is keptrotating relative to the motor-pump frame 2 by at least one lug orconnecting rod directly or indirectly fastened to the motor-pump frame2, the fastening of said lug and/or connecting rod to said frame 2 beingable to provide several degrees of freedom to accommodate the operationof the hydraulic motor-pump 1 according to the invention, whereas saidlug and/or connecting rod may be replaced by any other mechanical meansmaking it possible to stop the rotation of the input/output spool valve43 along the axis of rotation of the motor-pump central rotor 3.

It will be noted that according to one particular embodiment of thehydraulic motor-pump 1 according to the invention, the connecting rodmay be connected to the peripheral rotor stator 65 such that when thelatter rotates under the action of a displacement-varying servomotor 68,said connecting rod simultaneously rotates the input/output spool valve43 relative to the motor-pump frame 2, in the same direction, and with asimilar angular amplitude.

As shown by FIGS. 10 and 11, the input/output spool valve 43 is acylindrical stator 91 housed with slight play in a stator cylinder 92formed at the center of the motor-pump central rotor 3 and coaxiallythereto, said stator 91 containing an inner duct chamber 55 thatcommunicates on the one hand with the inner input/output duct 57, and onthe other hand with an inner duct input/output angular manifold 44included by said stator 91 on its periphery via a spool valveinput/output inner channel 53, while said stator 91 also contains anouter duct chamber 56 that communicates on the one hand with the outerinput/output duct 58 and on the other hand with an outer ductinput/output angular manifold 89 also included by said stator 91 in itsperiphery via another inner spool valve input/output channel 53, theangular manifolds 44 and 89 for example being made up of radial groovesthat are formed on an angular portion substantially smaller than 125°and which are angularly offset relative to one another by approximately180°, and across from which the central rotor input/output orifice 16periodically becomes positioned during the rotation of the motor-pumpcentral rotor 3 so as to allow a motor-pump oil 114 to circulate betweensaid duct chambers 55, 56 and the hydraulic cylinder 14.

It will be noted that the cylindrical stator 91 includes, on the side ofthe inner duct input/output angular manifold 44, at least one outer ductradial force equalizing groove 90 that communicates with the outer ductchamber 56 via a spool valve equalizing inner channel 54, while saidstator 91 also includes at least one inner duct radial force equalizinggroove 45 that communicates with the inner duct chamber 55 via anotherspool valve equalizing inner channel 54, said groove 45 being situatednext to the outer duct input/output angular manifold 89 and the surfaceof the outer duct radial force equalizing groove 90 being calculated sothat the radial force produced on the stator 91 by the pressureprevailing in the outer duct input/output angular manifold 89 issubstantially equal to the antagonistic radial force produced on thestator 91 by the pressure prevailing in said equalizing groove 90.

This strategy may apply identically regarding the inner duct radialforce equalizing groove 45, which may offset the radial force producedon the stator 91 by the inner duct input/output angular manifold 44.

As shown in FIG. 10, the cylindrical stator 91 may include an axialsealing groove 93 near at least one of its axial ends.

It will be noted that according to one particular embodiment of thefixed or variable displacement hydraulic motor-pump 1 according to theinvention illustrated in FIGS. 18 and 19, the input/output spool valve43 may be an axial stator 96 made up of a distributing flange 97 and anequalizing flange 98 that are placed axially on either side of themotor-pump central rotor 3, across from a distribution face 103 and anequalizing face 104 formed on said rotor 3, respectively, said flanges97, 98 being mechanically connected to each other by an axial statorcentral hub 99 that passes axially through said central rotor 3 via astator cylinder 92 arranged at the center of said central rotor 3 andcoaxially thereto, said stator 96 containing an inner duct chamber 55that communicates on the one hand with the inner input/output duct 57,and on the other hand with an inner duct input/output angular manifold44 arranged axially on the inner face of the distributing flange 97 viaa spool valve input/output inner channel 53, while said stator 96 alsocontains an outer duct chamber 56 that communicates on the one hand withthe outer input/output duct 58, and on the other hand with an outer ductinput/output angular manifold 89 also arranged axially on the inner faceof the distributing flange 97 via another spool valve input/output innerchannel 53, the angular manifolds 44 and 89 for example being made up ofaxial grooves arranged on said inner face over an angular portionsubstantially smaller than 180° and angularly offset relative to oneanother by approximately 180°, and which are found regularly positionedacross from the central rotor input/output orifice 16 during therotation of the motor-pump central rotor 3 so as to allow a motor-pumpoil 114 to circulate between the duct chambers 55, 56 and the hydrauliccylinder 14.

FIGS. 18 and 19 show that the inner duct chamber 55 communicates with aninner duct axial force equalizing groove 100 arranged axially on theinner face of the equalizing flange 98 via a spool valve equalizinginner channel 54, while the outer duct chamber 56 communicates with anouter duct axial force equalizing groove 101 also arranged axially onthe inner face of the equalizing flange 98 via another spool valveequalizing inner channel 54, the surface of the outer duct axial forceequalizing groove 101 being calculated so that the axial force producedon the axial stator 96 by the pressure prevailing in the outer ductinput/output angular manifold 89 is substantially equal to theantagonistic axial force produced on said stator 96 by the pressureprevailing in said equalizing groove 101. This strategy may applyidentically regarding the inner duct axial force equalizing groove 100,such that the latter produces, on the stator 96, a force of the sameintensity as that produced by the inner duct input/output angularmanifold 44 on said stator 96.

Furthermore, as shown in FIGS. 18 and 19, the distributing flange 97and/or the equalizing flange 98 includes a radial sealing groove 102 atleast at one of its radial ends.

It will be noted that the axial stator central hub 99 may include anaxial sealing groove 93 at least at one of its axial ends or at anypoint along its length.

As illustrated in FIG. 10, all or part of the inner duct input/outputangular manifold 44, the outer duct input/output angular manifold 89,the outer duct radial force equalizing groove 90, the inner duct radialforce equalizing groove 45, the axial sealing groove 93, the inner ductaxial force equalizing groove 100, the outer duct axial force equalizinggroove 101 or the radial sealing groove 102, may be provided with aspool valve groove segment 46 that prevents an excessive quantity ofpressurized motor-pump oil 114 from leaking between the cylindricalstator 91 and the stator cylinder 92, or between the distributing flange97 and the distribution face 103 and/or between the equalizing flange 98and equalizing face 104, said segment 46 being able to be of any typeknown by those skilled in the art, irrespective of the material, thegeometry or treatment of the surface, which may for example be nitrided,cemented and/or coated with DLC (Diamond-Like Carbon) or any other hardcoating and/or coating with a low friction coefficient.

As shown in FIGS. 12 and 13, the fixed or variable displacementhydraulic motor-pump 1 provides that the spool valve groove segment 46may have at least one segment flank 94 that laterally establishessealing with the cylindrical stator 91 or the axial stator 96, and atleast one segment sealing line 49 which on the one hand comes intocontact with the motor-pump central rotor 3 to form sealing, and on theother hand is subject to a force that tends to press it on said rotor 3due to the thrust exerted by a pressurized motor-pump oil 114 containedby the cylindrical stator 91 or the axial stator 96 on the spool valvegroove segment 46, said force being limited due to a small sprayedsurface 161 subjected to the pressure of said oil 114 offered by saidsegment 46 that results from a segment force reacting shoulder 50included by said segment 46 that cooperates with another shoulder 162formed in the cylindrical stator 91 or in the axial stator 96, saidshoulders 50, 162 making it possible simultaneously to give said segment46 a sufficient width and stiffness at the segment sealing line 49,limit said sprayed surface 161, and limit the Hertz pressure exerted bysaid sealing line 49 on the motor-pump central rotor 3.

It will be noted that according to one particular embodiment of thehydraulic motor-pump 1 according to the invention, the spool valvegroove segment 46 may be made up of two half-segments 95, the firsthalf-segment 95 preventing the motor-pump oil 114 from leaving theangular manifold 44, 89 or the equalizing groove 90, 45, whereas thesecond prevents said oil 114 from entering therein. It will be notedthat the segment force reacting shoulder 50 may include at least onesegment decompression recess 52, while the two half-segments 95 mayeither be independent of one another, or be made from the same materialbillet. In that case, it is possible to provide—as clearly shown inFIGS. 12 and 13—one or more segment decompression orifice(s) 51 radiallyarranged between the two half-segments 95.

It will be noted that the spool valve groove segment 46 may be kept incontact with the motor-pump central rotor 3 by a segment groove bottomspring 47 that may be made up of a corrugated metal strip, a helicalspring, with any shape whatsoever appropriate for the profile of thesegment foot that works as a spring as illustrated in FIGS. 12 and 13,or any other means known by those skilled in the art and making itpossible to produce a spring providing the most uniform possible thrustover said segment 46 to keep it in contact with the motor-pump centralrotor 3, the surface of the latter for example being able to benitrided, cemented and/or coated with DLC (Diamond-Like Carbon) or anyother hard coating and/or coating with a low friction coefficient,regarding at least the part of said central rotor 3 that is exposed tocontact with said segment 46.

It will also be noted that the spool valve groove segment 46 may be madeup of two half-segments 95 that each have at least one segment flank 94kept in contact with the cylindrical stator 91 or the axial stator 96 bya segment separator spring 48 that may be made up of at least onecorrugated metal strip, at least one helical spring, of any shapewhatsoever suitable for the section profile of said segment 46, saidshape working as a spring as illustrated in FIGS. 12 and 13, or anyother means known by those skilled in the art and making it possible toproduce a spring providing the most uniform possible thrust on saidsegment flanks 94 to keep them in contact with said cylindrical stator91 or said axial stator 96.

According to one particular embodiment of the fixed or variabledisplacement hydraulic motor-pump 1 according to the inventionillustrated in FIGS. 10 and 11, the inner input/output duct 57 issecured in the input/output spool valve 43 and/or in the motor-pumpframe 2 by one or the other of the ends of said duct 57 using at leastone fixed duct covering ball joint 59 and/or at least one sliding ductcovering ball joint 60, said ball joint 59, 60 having a covering balljoint step 105 that can rest on a covering ball joint seat 64 so as toproduce—with the input/output spool valve 43 and/or the motor-pump frame2—sealing on the one hand, and a ball joint connection on the otherhand, said step 105 and/or said seat 64 having a truncated sphere shape.

It will be noted that, according to one particular embodiment of thehydraulic motor-pump 1 according to the invention, the covering balljoint step 105 and the covering ball joint seat 64 may be nitrided,cemented and/or coated with DLC (Diamond-Like Carbon), or any other hardcoating and/or coating with a low friction coefficient.

It will also be noted that the fixed duct covering ball joint 59 may bekept in contact with its covering ball joint seat 64 by a covering balljoint spring that bears on the one hand on the input/output spool valve43 or on the motor-pump frame 2 or on a sliding duct covering ball joint60, and on the other hand, directly or indirectly on said fixed coveringball joint 59, said spring being able to be a helical spring, acorrugated elastic washer or “Belleville” washer, or any other spring ofany type, geometry or material.

As illustrated by FIGS. 10 and 11, the sliding duct covering ball joint60 may be made up of at least one sliding covering half-ball joint 107axially passed through by the inner input/output duct 57, said half-balljoint 107 being able to translate axially and sealably relative to saidinner duct 57, whereas said half-ball joint 107 is kept in contact withits covering ball joint seat 64 by a covering ball joint spring 106 thatcan bear on the one hand on the input/output spool valve 43 or on themotor-pump frame 2 or on another sliding covering half-ball joint 107,and on the other hand, directly or indirectly on said sliding coveringhalf-ball joint 107, said spring 106 in particular being able to be ahelical spring, a corrugated elastic washer or “Belleville” washer, orany other spring of any type, geometry or material.

According to one particular embodiment of the hydraulic motor-pump 1according to the invention, the inner cylindrical surface of the slidingcovering half-ball joint 107 or the outer cylindrical surface of theinner input/output duct 57 may include a groove in which a slidingcovering ball joint 61 is housed that prevents any leakage of motor-pumpoil 114 between said half-ball joint 107 and said duct 57.

It will be noted that the outer input/output duct 58 may be secured inthe input/output spool valve 43 and/or in the motor-pump frame 2 by oneor the other of the ends of said duct 58 using at least one fixed ductcovering ball joint 59, said ball joint 59, 60 having a covering balljoint step 105 that can rest against a covering ball joint seat 64 so asto produce—with the input/output spool valve 43 and/or the motor-pumpframe 2—sealing on the one hand, and a ball joint connection on theother hand, said step 105 and/or said seat 64 having a truncated sphereshape.

It will be noted that, according to one particular embodiment of thehydraulic motor-pump 1 according to the invention, the covering balljoint step 105 and the covering ball joint seat 64 may be nitrided,cemented and/or coated with DLC (Diamond-Like Carbon) or any other hardcoating and/or coating with a low friction coefficient.

FIGS. 10 and 11 show that the inner duct chamber 55 may be closed by aninner duct plug 66 that may or may not—depending on the selectedembodiment of the hydraulic motor pump 1 according to the invention—bepassed through by the inner input/output duct 57, and include a coveringball joint seat 64 that cooperates with a fixed duct covering ball joint59 or a sliding duct covering ball joint 60 included by said inner duct57.

Furthermore, the outer duct chamber 56 may be closed by an outer ductplug 67 that is passed through by the outer input/output duct 58, saidplug 67 being able—depending on the selected embodiment of the hydraulicmotor-pump 1 according to the invention—to include a covering ball jointseat 64 that cooperates with a fixed duct covering ball joint 59 or asliding duct covering ball joint 60 included by said outer duct 58.

It will be noted that the inner input/output duct 57 may be housedentirely or partially inside the outer input/output duct 58, the workingsection of the latter through which a motor-pump oil 114 circulates thatis pumped by the hydraulic motor-pump 1 according to the invention thusbeing decreased from the total section of the inner input/output duct57.

FIGS. 10 and 11 as well as FIGS. 28 to 31 show that the motor-pump frame2 may comprise a connection satellite 62 in which the inner input/outputduct 57 and/or the outer input/output duct 58 are secured.

According to one particular embodiment of the hydraulic motor pump 1according to the invention shown in FIGS. 1 to 6, FIG. 8 and FIG. 22,the peripheral rotor stator 65 is articulated on the angularsynchronizing pinion axle 81 around which it can rotate under the actionof a displacement-varying servomotor 68, said servomotor 68 thus beingable to pivot said stator 65 by several degrees around said pinion axle81 so as to make said stator 65 more or less off-centered relative tothe motor-pump central rotor 3 so that the hydraulic piston 13 performsa translational movement in the hydraulic cylinder 14 with a greater orlesser amplitude from a zero amplitude corresponding to a zerodisplacement of the hydraulic motor-pump 1 according to the inventionshown in FIG. 5, up to a maximum amplitude corresponding to a maximumdisplacement of said motor-pump 1 shown in FIG. 6.

It will be noted that the displacement-varying servomotor 68 may be asingle- or double-acting hydraulic cylinder, an electric actuator with ascrew, or any other actuator known by those skilled in the art making itpossible to pivot the peripheral rotor stator 65 around the angularsynchronizing pinion axle 81.

As illustrated in FIGS. 1 to 6, the displacement-varying servomotor 68may be a servomotor rotary electric motor 30 that can rotate adisplacement-varying ring driving pinion 108 in one direction or theother using a servomotor reducing gear 31, said pinion 108 being able torotate in a bearing formed in the motor-pump frame 2 and being able torotate a displacement-varying ring 109 secured to the peripheral rotorstator 65, the pitch circle of said ring 109 being centered on theangular synchronizing pinion axle 81.

It will be noted that the servomotor rotary electric motor 30 may usealternating or direct current, may or may not be of the stepping type,synchronous or asynchronous, with permanent magnets or brushes, and ingeneral, of any type known by those skilled in the art and controlled byan electronic management device that operates using control software.According to one particular embodiment of the hydraulic motor-pump 1according to the invention, the servomotor reducing gear 31 may be madeup of a cascade of pinions, and/or at least one planetary gear setand/or at least one worm screw and may be connected to the servomotorrotary electric motor 30 on the one hand and/or to thedisplacement-varying ring-driving pinion 108 on the other hand by atransmission shaft that may or may not be provided with a Cardan jointor a homokinetic joint that does or does not cooperate with a chain,belt, or any other mechanical transmission means known by those skilledin the art.

As shown in FIGS. 20 and 21, the fixed or variable displacementhydraulic motor-pump according to the invention may include rephasingmeans 197 that are inserted between the peripheral rotor angular synchroring 42 and the central rotor angular synchro ring 11.

Said means 197 may be actuated by the displacement-varying servomotor 68when the latter rotates the peripheral rotor stator 65 around theangular synchronizing pinion axle 81.

It will be noted that said means 197 may be mechanical and/or hydraulicand/or electric and may be based on a principle similar to that of thecamshaft phase shifters found on reciprocating internal combustionengines or that of any phase shifter known by those skilled in the artof any type whatsoever. The rephasing means 197 in particular allow thetangential arm antifriction roller 28 to remain positioned relative tothe tangential arm rolling track 26 so as to be able to cooperate withthe latter irrespective of the displacement imposed by thedisplacement-varying servomotor 68 on the hydraulic motor-pump 1according to the invention.

As shown in FIGS. 20 and 21, the rephasing means 197 are made up of atleast one intermediate rephasing gear 198 including at least one toothedrephasing wheel 199 rotating around at least one rephasing axle 200secured to the peripheral rotor stator 65, said gear 198 being insertedbetween the peripheral rotor angular synchro ring 42 and the angularsynchronizing pinion 12.

It will be noted that according to this particular configuration of thehydraulic motor-pump 1 according to the invention, when thedisplacement-varying servomotor 68 keeps the peripheral rotor stator 65immobile relative to the motor-pump frame 2, the speed and direction ofrotation of the peripheral rotor angular synchro ring 42 are identicalto those of the central rotor angular synchro ring 11. To guarantee thisresult, the transmission means connecting the angular synchronizingpinion 12 to the central rotor angular synchro ring 11 may be providedto be identical to those connecting said pinion 12 to the peripheralrotor angular synchro ring 42, or at the very least produce the sameeffects as the latter.

According to one particular embodiment of the hydraulic motor-pump 1according to the invention shown in FIG. 23 and FIGS. 28 to 31, theinner input/output duct 57 and the outer input/output duct 58 may bedirectly or indirectly connected, respectively, with the input or theoutput of at least one second fixed or variable displacement hydraulicmotor-pump 125, the fixed or variable displacement hydraulic motor-pump1 and the second fixed or variable displacement motor-pump 125 togetherforming a hydraulic transmission device 63 that may or may not varycontinuously, said second motor-pump 125 being able—according to oneparticular embodiment—to be identical to the fixed or variabledisplacement hydraulic cylinder motor-pump 1 according to the invention,or have an external gear, internal gear, vanes, axial or radial pistons,with or without variable displacement and in general, any type knownfrom the prior art.

It will be noted that the hydraulic transmission device 63 may either beused alone, or be mounted in series or in parallel with any othertransmission device known by those skilled in the art.

According to one particular embodiment of the hydraulic motor-pump 1according to the invention shown in FIG. 23 and FIGS. 28 to 31, thecentral rotor power takeoff 4 of the fixed or variable displacementmotor-pump 1 is mechanically connected to at least one drive motor 123included by a motor vehicle 110, while the second fixed or variabledisplacement hydraulic motor-pump 25 is mechanically connected to atleast one drive wheel or track 124 included by said vehicle 110, or viceversa, the drive motor 123 being able to be of the heat or electric typeand able to be controlled by a management computer of the drive motor170, while the motor vehicle 110 may be an individual vehicle, a utilityvehicle, a heavy truck, a construction vehicle, an agricultural tractor,or any other self-propelled vehicle, including an airplane or ship, thedrive wheel or track 124 in that case being replaced by a propelleroperating in the air or water, respectively.

It will be noted that if the second fixed or variable displacementhydraulic motor-pump 125 is identical to the fixed or variabledisplacement hydraulic motor-pump 1 according to the invention, thecentral rotor power takeoff 4 of the hydraulic motor-pump 1 is connectedby mechanical means to the drive motor 123, while the central rotorpower takeoff 4 of the second hydraulic motor-pump 125 is connected bymechanical means to the drive wheel or track 124.

Irrespective of the configuration selected to produce the hydraulicmotor-pump 1 according to the invention, said mechanical means may bemade up of a transmission shaft, a differential axle assembly, aplanetary gear set, a Cardan joint or homokinetic joint, a belt, achain, a cascade of pinions, a gear of any type whatsoever, or anymechanical transmission means known by those skilled in the art. It willbe noted that, according to one particular embodiment of the hydraulicmotor-pump 1 according to the invention, the hydraulic transmissiondevice 63 advantageously makes it possible to replace the differentialaxle assembly ordinarily used on motor vehicles, for example byproviding a fixed or variable displacement hydraulic motor-pump 1connected to the drive motor 123 of the motor vehicle 110 thatcooperates with two second fixed or variable displacement hydraulicmotor-pumps 125 each connected to a drive wheel or track 124 of a sameaxle of said vehicle 110.

According to this particular configuration shown in FIGS. 29 and 30, thedistribution of the motor or pump torque between said drive wheels ortracks 124 is done either naturally, the flow rate of a motor-pump oil114 circulating between the different motor-pumps 1, 125 beingdistributed between said two second fixed or variable displacementhydraulic motor-pumps 125 as a function of said motor or pump torqueimparted to each of said second motor-pumps 125 by the drive wheel ortrack 124 that they are responsible for rotating, or dynamically, byadjusting the displacement of each said second motor-pump 125 as afunction of the turning radius and optionally the speed of the motorvehicle 110 respectively detected by a turning angle sensor and atachymeter included by said vehicle 110 with which at least oneaccelerometer may optionally be associated. It will be noted that if thedistribution of the motor or pump torque between said drive wheels ortracks 124 is done dynamically, the motor vehicle 110 offers bettergrip. It will be noted that this non-limiting example embodiment of thehydraulic motor-pump 1 according to the invention can be transposed tomotor vehicles with two wheel drive, four-wheel drive or several drivewheels, without any number-based limitation. It will be noted that thedrive motor 123 of the motor vehicle 110 may in particular be of thediesel spark ignition reciprocating internal combustion type, or may bemade up of one or more axial and/or radial turbines, in particular usinga configuration similar to that described in French patent applicationno. FR 12/59827 belonging to the applicant and illustrated in FIG. 31.

According to one particular embodiment of a hydraulic motor-pump 1according to the invention shown in FIG. 23, the inner input/output duct57 may be connected with at least one high-pressure accumulator 71, thediagrammatic cross-section of which is shown in FIGS. 24 to 27, by atleast one inner duct high-pressure accumulator valve 112.

Furthermore, the outer input/output duct 58 may be connected with atleast one high-pressure accumulator 71 by at least one outer ducthigh-pressure accumulator valve 128.

The inner input/output duct 57 may also be connected with at least onelow-pressure accumulator 118, the diagrammatic cross-section of which isshown in FIGS. 24 to 27, by at least one inner duct low-pressureaccumulator valve 129.

As shown in FIG. 23, the outer input/output duct 58 may be connectedwith at least one low-pressure accumulator 118 by at least one outerduct low-pressure accumulator valve 130, the accumulator valves 112,128, 129, 130 being able to be of the ball, drawer, sliding gate,delivery valve, needle, flap, tube type similar to the patentapplication belonging to the applicant published under no. FR 2,969,705,or any covering means maneuvered by an electric, electromagnetic,pneumatic, mechanical or hydraulic actuator, while the high-pressureaccumulator 71 and/or the low-pressure accumulator 118 may for examplehave a membrane or a piston and comprise a gas, a fluid, or at least onespring.

As illustrated in FIG. 24, the high-pressure accumulator 71 and/or thelow-pressure accumulator 118 may include an accumulator pressure sensor69 that informs a motor-pump management computer 70 of the pressureprevailing in the or said accumulator(s) 71, 118. Furthermore, all orpart of the inner and/or outer surface of the or said accumulator(s) 71,118 may be covered with a heat transfer material, for example rock wool,a cellular structure, or any arrangement known by those skilled in theart that makes it possible to conserve heat. According to onealternative embodiment of the hydraulic motor-pump 1 according to theinvention shown in FIG. 23, the inner input/output duct 57 and/or theouter input/output duct 58 may be connected with the low-pressureaccumulator 118 via a low-pressure accumulator check valve 143 thatallows a motor-pump oil 114 to circulate from said accumulator 118 tothe inner duct 57 and/or said outer duct 58, but not the reverse.Furthermore, FIG. 23 also shows that the inner input/output duct 57and/or the outer input/output duct 58 may be connected to a motor-pumpoil reservoir 121 by a pressure limiting valve 144, the latterprotecting the main bodies making up said hydraulic motor-pump 1 fromany overpressure that could damage them.

As illustrated in FIGS. 25 to 27, the high-pressure accumulator 71and/or the low-pressure accumulator 118 may comprise at least oneaccumulator separator piston 72 capable of moving sealably in anaccumulator blind cylinder 113, said piston 72 delimiting, with saidcylinder 113, a gas compartment 116 containing a pressurized gas 115 andan oil compartment 117 containing a motor-pump oil 114, the lattercompartment 117 being able to be connected with the inner input/outputduct 57 and/or the outer input/output duct 58 during the operation ofthe hydraulic transmission device 63, while the pressurized gas 15 maybe nitrogen or any other gas whereof the characteristics are compatiblewith the desired pressure variations, in the desired temperature range.

It will be noted that—as shown in FIGS. 25 to 27—the accumulatorseparator piston 72 may include at least one accumulator piston joint122 and/or a segment in its periphery to produce, with the accumulatorblind cylinder 113, the best possible sealing, said joint 122 being ableto be toroid, with a lip, composite, or made with any material orgeometry whatsoever, whereas if it is a segment, the latter may also beof any type known by those skilled in the art, without limitation. Itwill also be noted that the accumulator blind cylinder 113 may include ahemispherical cup at each of its ends and/or be essentially made up ofand/or coated with steel and/or aluminum and/or composite material, inparticular able to integrate high-strength carbon fiber.

FIGS. 25 to 27 show that the oil compartment 117 may include anaccumulator closing gate 73 that the accumulator separator piston 72 canpress on an accumulator gate seat 74 by pushing on a high-stiffnessresisting spring 76 inserted between said piston 72 and said gate 73, soas to sealably isolate said compartment 117 from said inner input/outputduct 57 and/or said outer input/output duct 58, said gate 73cooperating—unlike the high-stiffness resisting spring 76—with alow-stiffness resisting spring 75 that tends to separate said gate 73from said seat 74, said gate 73 being able to include the shouldersnecessary for said springs 75, 76 to remain centered on said gate 73.

FIGS. 25 and 26 show that the accumulator separator piston 72 may pushon the high-stiffness resisting spring 76 by means of a high-stiffnessspring plunger 74 that is guided in longitudinal translation by a gateand plunger guide 78 secured to the high-pressure accumulator 71 and/orthe low-pressure accumulator 118, said gate guide 78 also guiding theaccumulator closing gate 73 and including a plunger stop 79 thatdetermines the maximum movement of the high-stiffness spring plunger 77toward the accumulator separator piston 72. If the gate and plungerguide 78 is an independent piece, it may be secured to the high-pressureaccumulator 71 and/or the low-pressure accumulator 118 by welding,screwing, crimping, or by any fastening means known by those skilled inthe art. Whatever the configuration, the gate and plunger guide 78 mayinclude means for connecting to any hydraulic duct, irrespective of thetype of the latter.

According to this particular configuration, the gate and plunger guide78 may include at least one radial gate guide orifice 80 that connectsthe oil compartment 117 with the accumulator gate seat 74 so as to allowthe motor-pump oil 114 to circulate between the inner input/output duct57 and/or the outer input/output duct 58 and said oil compartment 117.According to one particular embodiment of the hydraulic motor-pump 1according to the invention, the gate and plunger guide 78 may be made upof an open-worked tube that has several radial gate guide orifices 80,or a support structure resulting in gate guide radial orifices 80 with alarge section.

FIG. 22 shows that the high-pressure accumulator 71 and/or thelow-pressure accumulator 118 may be connected to the inner input/outputduct 57 and/or to the outer input/output duct 58 by means of anaccumulator locking valve 145 that can sealably isolate said accumulator71, 118 from said inner duct 57 and/or said outer duct 58, said lockingvalve 145 being sealed enough when it is closed for a motor-pump oil 114contained by said high-pressure accumulator 71 and/or said low-pressureaccumulator 118 not to be able to leave said accumulator 71, 118 even ifthe hydraulic motor-pump 1 according to the invention remains unused forlong periods of time. According to one non-limiting example of theaccumulator locking valve 145, the latter may be made up of a ballresting on a seat from which it may be separated by a touch needle movedby an electric, pneumatic or hydraulic motor.

FIG. 22 shows that the low-pressure accumulator 118 is supplied withmotor-pump oil 114 by at least one low-pressure pump 119 driven by alow-pressure pump motor 120, the intake duct of said pump 119 beingconnected to a motor-pump oil reservoir 121 while its discharge duct isconnected with said accumulator 118, said pump 119 being able to have anexternal gear, internal gear, vanes, axial radial pistons, a variable ornon-variable displacement, and in general, of any type known by thoseskilled in the art, while the low-pressure pump motor 120 may beelectric, thermal or hydraulic and may be connected to the low-pressurepump 119 by any transmission means also known by those skilled in theart such as a shaft, a Cardan joint or a homokinetic joint, a belt, achain or a gear of any type whatsoever, and irrespective of whether saidmeans cooperate with a reducing gear or a variable speed transmission.

It will be noted that according to one particular embodiment of thehydraulic motor-pump 1 according to the invention shown in FIG. 23, thelow-pressure accumulator 118 may be provided with an accumulatorpressure sensor 69 that returns the pressure prevailing in saidaccumulator 118 to a motor-pump management computer 70 such that thelatter controls the low-pressure pump 119 so that it continuously keepsthe pressure prevailing in said accumulator 118 above a certain value.Furthermore, as illustrated in FIG. 23, the discharge duct of thelow-pressure pump 120 may include a low-pressure pump check valve 141that allows the motor-pump oil 114 to go from said pump 120 to thelow-pressure accumulator 118 but not the reverse, while the intake ductof said pump 119 can include a low-pressure pump intake filter 142.According to one particular embodiment of the hydraulic motor-pump 1according to the invention, the motor-pump oil reservoir 121 may beformed in the motor-pump frame 2.

According to one particular embodiment of the hydraulic motor-pump 1according to the invention shown in FIG. 23, the inner input/output duct57 may be connected by an inner duct exchanger-dissipater valve 131 withat least one exchanger-dissipater inner duct 135 included by a pressureloss exchanger-dissipater 126, said duct 135 comprising at least onedissipater heat exchange outer surface 136 that is in contact with acoolant gas or a coolant liquid, said outer surface 136 being able to bemade up of the outer wall of the inner duct 135 possibly provided withfins, patterns or cooling protuberances. According to the presentinvention, the exchanger-dissipater inner duct 135 cooperates with, orincludes, at least one throat 166 and/or a winding or labyrinthine pathand/or a pressure-limiting valve that produces a pressure loss causingthe pressure of a motor-pump oil 114 circulating in said inner duct 135to drop, said pressure drop being provided to heat the motor-pump oil114 that is simultaneously cooled by its contact with said inner duct135 which, due to the dissipater heat exchange outer surface 136,transfers the heat from said oil 114 to the coolant gas or coolantliquid.

According to one particular embodiment of the hydraulic motor-pump 1according to the invention, the pressure loss exchanger-dissipater 126can be used to brake the drive motor 123 of the motor vehicle 110 whenstarting cold to accelerate the temperature increase of said motor 123when the latter is a reciprocating internal combustion motor, thedissipater heat exchange outer surface 136 in that case being put incontact with the coolant liquid and/or lubricating oil of said motor123. Furthermore, the pressure loss exchanger-dissipater 126 may be usedto brake the motor vehicle 110 when the latter goes down a slope, saidexchanger-dissipater then constituting a hydraulic decelerator. Thepressure loss exchanger-dissipater 126 can also be used during thebraking phase of the motor vehicle 110 to relieve the disc brakes 172 ordrum brakes so as to limit the temperature increase and wear of saidbrakes. In the latter case, the dissipater heat exchange outer surface136 may be put in contact with ambient atmospheric air to cool themotor-pump oil 114 circulating in the dissipater-exchanger inner duct135, the cooling produced by said air replacing or being added to thatproduced by the coolant liquid and/or the lubricating oil of the drivemotor 123. It will be noted that the input or the output of the pressureloss exchanger-dissipater 126 may include at least one dissipater checkvalve 169 that forces the motor-pump oil 114 coming—depending on thecase—from the inner input/output duct 57 or the outer input/output duct58, only to circulate in one direction.

According to one particular embodiment of the hydraulic motor-pump 1according to the invention shown in FIG. 23, the outer input/output duct58 may be connected by an outer duct exchanger-dissipater valve 132 withat least one exchanger-dissipater inner duct 135 included by a pressureloss exchanger-dissipater 126, said duct 135 comprising at least onedissipater heat exchange outer surface 136 that is in contact with acoolant gas or a coolant liquid, the configuration, operation andexpected results of the pressure loss exchanger-dissipater 126 beingidentical to those provided when the inner input/output duct 57 isconnected with said exchanger-dissipater 126, while saidexchanger-dissipater valves 131, 132 may be of the ball, drawer, slidinggate, delivery valve, needle, flap, tube type similar to the patentapplication belonging to the applicant published under no. FR 2,969,705,or any covering means maneuvered by any electric, electric, pneumatic,mechanical or hydraulic actuator.

FIG. 23 shows that the inner input/output duct 57 may be connected witha secondary hydraulic motor 127 by an inner duct secondary motor valve133.

As an alternative that is not shown, the outer input/output duct 58 maybe connected with a secondary hydraulic motor 127 by an outer ductsecondary motor valve, the latter and the inner duct secondary motorvalve 133 being able to be of the ball, drawer, sliding gate, deliveryvalve, needle, flap, tube type similar to the patent applicationbelonging to the applicant published under no. FR 2,969,705, or anycovering means maneuvered by any electric, electromagnetic, pneumatic,mechanical or hydraulic actuator, while said hydraulic motor 127 mayhave an external gear, internal gear, vanes, axial or radial pistons,with or without variable displacement and in general, any type known bythose skilled in the art, and may drive an electric alternator 163, asteering assistance device, an air conditioning compressor 164, aturbocharger shaft, in particular to reduce the response time of thelatter, or any other accessory 165 equipping a motor vehicle 110 or thatis part of a system that does or does not comprise a hydraulictransmission device 63.

It will be noted that the input or output of the secondary hydraulicmotor 127 may include a secondary hydraulic motor check valve 111 thatallows the motor-pump oil 114 coming from the inner input/output duct 57or outer input/output duct 58, depending on the case, to circulate inthe required direction to drive the motor 127, but not in the oppositedirection. It will be noted that, according to one particular embodimentof the hydraulic motor-pump 1 according to the invention, the secondaryhydraulic motor 127 may be mechanically connected to any accessory 165by means of a freewheel known by those skilled in the art, such thatsaid accessory 165 may be rotated by another driving system such as abelt or chain without said other system being able to rotate thesecondary hydraulic motor 127 if the latter is not supplied withmotor-pump oil 114. This particular embodiment may also provide thatsaid other drive system is also connected to said accessory 165 by afreewheel such that the secondary hydraulic motor 127 cannot rotate saidsystem if the latter is not itself rotated by another driving source.

In any case, the freewheels included, in this case, by the secondaryhydraulic motor 127 and said other driving system do not oppose thelatter two cooperating simultaneously to rotate said accessory 165.

As shown in FIG. 33, the secondary hydraulic motor 127 may be made up ofat least one hydraulic turbine 137 mounted on a hydraulic turbine shaft138 that includes at least one hydraulic turbine blade 139 on which atleast one hydraulic turbine injector 140 can axially and/or radiallyspray a jet of a motor-pump oil 114 such that said blade 139 rotatessaid turbine shaft 138, the latter being mechanically connected,directly or indirectly, to one or more accessories 165 by a fixed orvariable transmission and/or by a reducing gear.

According to the invention, the latter two components may have gears, achain, a belt, rollers, or be of any other type known by those skilledin the art, and the or said accessory or accessories may equip a motorvehicle 110 or be part of a system that does or does not comprise ahydraulic transmission device 63.

FIGS. 28 to 31 show that the hydraulic motor-pump 1 according to theinvention may include a motor-pump management computer 70 that controlsthe displacement-varying servomotor 68 to control the displacement ofthe fixed or variable displacement hydraulic motor-pump 1, includingthat making up the hydraulic transmission device 63, irrespective ofwhether the latter is incorporated into a motor vehicle 110, saidcomputer 70 also being able to control the inner duct high-pressureaccumulator valve 112, and/or the outer duct high-pressure accumulatorvalve 128 and/or the inner duct low-pressure accumulator valve 129and/or the outer duct low-pressure accumulator valve 130 and/or theaccumulator locking valve 145 and/or the low pressure pump motor 120and/or the inner duct exchanger-dissipater valve 131 and/or the outerduct exchanger-dissipater valve 132 and/or the inner duct secondarymotor valve 133 and/or the outer duct secondary motor valve.

According to one non-limiting example embodiment of the hydraulicmotor-pump 1 according to the invention, the motor-pump managementcomputer 70 runs specific computer software and is connected to all orsome of the sensor(s) and actuator(s) included by the motor vehicle 110and its drive motor 123, such that the hydraulic transmission device 63that equips said vehicle 110 is contributing to the energy, safety,performance and comfort objectives set for the vehicle 110.

According to another non-limiting example embodiment of the hydraulicmotor-pump 1 according to the invention illustrated in FIG. 32, themotor-pump management computer 70 may be connected by wired, lighted orelectromagnetic information transmission means to at least one shiftinglever 146 and/or at least one shifting vane 147 and/or at least oneshifting button 148 and/or a clutch pedal 149 and/or a brake pedal 150and/or an accelerator pedal 151 included by a driving station 152comprised by the motor vehicle 110, the different components that aresaid lever 146, said vane 147, said button 148, the clutch pedal 149 andthe brake pedal 150 being able—according to one particular embodiment ofthe hydraulic motor-pump 1 according to the invention—to be removable,replaceable or retractable to allow the driver of the motor vehicle 110the possibility of configuring said vehicle 110 as desired based on theanticipated use of the hydraulic transmission device 63. In that case,sensors inform the motor-pump management computer 70 of the presence,absence or status of the removable, replaceable or retractablecomponents 146, 147, 148, 149, 150 such that said computer 70 canauthorize or prohibit certain operating modes of the hydraulictransmission device 63.

For example, for said computer 70 to be able to use the hydraulictransmission device 63 to reproduce the behavior of a manual gearshifter, it is necessary for the driver of the motor vehicle 110 to havepreviously installed a shifting lever 147 whereof the travel isconstrained in an “H” pattern; installed or unfolded the clutch pedal149; and replaced the wide brake pedal 150 used to emulate an automatictransmission with another, narrower brake pedal 150.

It will be noted that various additional functions may be provided tocontrol the hydraulic transmission device 63, such as a proportionalparking brake whereof the forward or backward incline imparts a lowforward or backward movement speed to the motor vehicle 110 inproportion to said incline. The same strategy may be established using aknob, the incline of the lever in that case being replaced by therotation of said knob in one direction or the other. Thus, said lever orsaid knob controlling the hydraulic transmission device 63 duringparking maneuvers may advantageously eliminate skidding of the brakes orhydrokinetic torque converters and the seizing associated with thepropulsion engine 123 caused by the transmissions according to the priorart.

According to another non-limiting example embodiment of the hydraulicmotor pump 1 according to the invention shown in FIG. 32, the motor-pumpmanagement computer 70 may also be connected by wired, lighted orelectromagnetic information transmission means (not shown) to at leastone transmission configuration button or knob 153 and/or a transmissionconfiguration screen 154 and/or a transmission configuration microphone155 and/or a transmission configuration speaker 156 included by adriving station 152 shown in FIG. 32 comprised by the motor vehicle 110,said button or knob 153, said screen 154, said microphone 155 and saidspeaker 156 forming a man-machine interface between the driver of themotor vehicle 110 and the motor-pump management computer 70, saidinterface in particular allowing said driver to configure the hydraulictransmission device 63 of the motor vehicle 110.

According to one particular embodiment of the hydraulic motor-pump 1according to the invention, the transmission configuration screen 154 isa touchscreen with a software interface that allows the driver of themotor vehicle 110 to choose—when the hydraulic transmission device 63 isused to reproduce the behavior of an automatic transmission with torqueconverter or a continuously variable transmission—between an “economy”mode, a “comfort” mode or a “sport” mode.

In the case where only one torque converter automatic transmission isemulated by the hydraulic transmission device 63, the number andstepping of the transmission ratios of said transmission can beprogrammed by the driver using said screen 154.

Said man-machine interface can also allow the driver to choose betweendifferent transmission ratio steppings when the hydraulic transmissiondevice 63 reproduces the operation of a manual transmission.Furthermore, as a non-limiting example, the intensity of the motor brakethat is reproduced by the pressure loss exchanger-dissipater 126 thatmay be included by the hydraulic transmission device 63, theprogressiveness of the clutch reproduced by said device 63 when thelatter emulates the operation of a manual transmission, or theprogressiveness of the torque converter when said device 63 reproducesthe behavior of an automatic transmission with torque converter, may beconfigured by the driver of the motor vehicle 110. It will be notedthat, according to one particular embodiment of the hydraulictransmission device 63, the motor brake may potentially be programmed bythe driver of the motor vehicle 110 to adapt automatically to thesteepness of the descents encountered during any travel. In that case,the motor-pump management computer 70 is for example coupled to aninclinometer and/or accelerometer.

OPERATION OF THE INVENTION

To illustrate the operation of the fixed or variable displacementhydraulic motor-pump (1), it has been chosen here to apply saidmotor-pump (1) to the hydraulic transmission device (63) connecting thedrive motor (123) of the motor vehicle (110) to the drive wheels (124)of said vehicle (110). This example embodiment of the hydraulicmotor-pump (1) is non-limiting and does not call into question thediversity and interest of its other applications in many industrialand/or household fields. According to said example, the second variabledisplacement hydraulic motor-pump (125) that is connected to the drivewheels (124) is identical to the variable displacement hydraulicmotor-pump (1) that is connected to the drive motor (123). In thatcontext, the operation of the fixed or variable displacement hydraulicmotor-pump (1) is as follows:

The drive motor (123), which is—according to this example—a heat enginewith reciprocating internal combustion spark ignition, rotates themotor-pump central rotor (3) using the central rotor power takeoff (4)to which its crankshaft (168) is connected. In so doing, said motor(123) rotates the motor-pump peripheral rotor (29), whereof theperipheral rotor angular synchro ring (42) is secured in rotation to thecentral rotor angular synchro ring (11) by the angular synchronizingpinion (12).

As shown in FIG. 6, the motor-pump peripheral rotor (29) may be keptoff-centered relative to the motor-pump central rotor (3) by itsdisplacement-varying servomotor (68). In that case, it will beunderstood that the hydraulic piston (13) performs a back-and-forthtranslational movement in the hydraulic cylinder (14). The input/outputspool valve (43) being oriented in the motor-pump frame (2) asillustrated in FIG. 11, it will be understood that relative to FIG. 6,when the hydraulic piston (13) moves away from the motor-pump centralrotor (3), the hydraulic cylinder (14) is connected by said spool valve(43) with the inner input/output duct (57), while when said piston (13)comes closer to said central rotor (3), said cylinder (14) is connectedby said spool valve (43) with the outer input/output duct (58). Thus,the hydraulic piston (13) and its hydraulic cylinder (14) together makeup a pump that sucks the motor-pump oil (114) into the innerinput/output duct (57), then discharges it into the outer input/outputduct (58).

According to one particular embodiment shown in FIGS. 3 to 7, 18 and 19,the motor-pump central rotor (3) can advantageously include three rowsof hydraulic pistons (13) each including four hydraulic pistons (13)uniformly distributed on the periphery of said central rotor (3) andangularly offset by 90°. The second row of hydraulic pistons (13) isangularly offset by 30° relative to the first, while in the samedirection, the third row is angularly offset by 30° relative to thesecond. Thus, the twelve hydraulic pistons (13) included by themotor-pump central rotor (3) are radially and uniformly distributedaround said rotor (3) by a distribution angle of 30°. This configurationwith twelve hydraulic pistons (13) guarantees a slightly pulsedoperation of the hydraulic motor-pump (1).

It will be noted that the particular mechanical configuration of thefixed or variable displacement hydraulic motor-pump (1) according to theinvention minimizes the friction losses and oil leaks from themotor-pump (114) that may be created during operation by said motor-pump(1). As a result of these first two features—which are among the majoradvantages of the hydraulic motor-pump (1) according to the invention—itis in particular possible for said motor-pump (1) to operate under veryhigh peak pressures, for example approximately 2000 bar.

As can be deduced from FIG. 6, when the hydraulic piston (13) issubjected to the pressure of the motor-pump oil (114) contained in thehydraulic cylinder (14), it exerts a force on the brace (82) that isguided in the plunger guide (19) and whereof the strut (83) bears theplunger path of contact on tangential arm (21). Consequently, said pathof contact (21) exerts a force of similar intensity on the tangentialarm bearing face on plunger (23), said force being passed on by saidtangential arm (22) to the tangential arm antifriction roller (28) viathe tangential arm rolling track (26) included by said arm (22). Lastly,said roller (28) passes said force on to the peripheral rotor rollingtrack (33), such that the hydraulic pump jointly made up of thehydraulic piston (13) and hydraulic cylinder (14) is actuated by theforce produced by said piston (13) on the motor-pump peripheral rotor(29), which reacts with a force of comparable intensity simultaneouslyproduced by said cylinder (14) and the motor-pump oil (114) that itcontains, on the motor-pump central rotor (3).

As shown in FIGS. 3 to 7, the particular mechanical configuration of thehydraulic motor-pump (1) according to the invention protects thehydraulic piston (13) from any radial force to which the pistons of thepiston hydraulic pumps according to the prior art are generallysubjected. Advantageously, the hydraulic motor-pump (1) according theinvention provides that said radial force is reacted in small part atthe contact between the strut (83) and the plunger guide (19), and forthe majority by the tangential arm (22) at its tangential arm axle (24)and in the longitudinal direction of said arm (22). Furthermore, thesimultaneous rotation at the same speed of the motor-pump central rotor(3) and the motor pump peripheral rotor (29) as provided by thehydraulic motor-pump (1) according to the invention effectively limitsthe distance variations occurring between the point of contact of thetangential arm antifriction roller (28) on the peripheral rotor rollingtrack (33) included by the inner surface of the motor-pump peripheralrotor (29) on the one hand, and the point of contact of saidantifriction roller (28) on the tangential arm rolling track (26)included by the tangential arm (22) on the other hand. Furthermore, saidremaining distance variations result in a contact that is not sliding,but rolling, the tangential arm antifriction roller (28) rolling on theone hand on the tangential arm rolling track (26), and on the other handon the peripheral rotor rolling track (33).

FIG. 6 also shows that the travel of the tangential arm antifrictionroller (28) is limited on the one hand relative to the tangential armrolling track (26) and on the other hand relative to the peripheralrotor rolling track (33), by the tangential arm roller rack (27) and bythe peripheral rotor roller ring (34) respectively included by saidtracks (26, 33), the roller pinion (87) comprised by said roller (28)simultaneously cooperating with said rack (27) and said ring (34) suchthat said roller (28) preserves an operating position as close aspossible to that making it possible to minimize the friction losses ofthe hydraulic motor-pump (1) according to the invention.

FIGS. 5 and 6 show that the tangential arm antifriction roller (28) isalways kept simultaneously pressed on the tangential arm rolling track(26) and the peripheral rotor rolling track (33) by the tangential armreturn spring (25), such that said roller (28) cannot be thrown out ofgear either from the tangential arm roller rack (27) or from theperipheral rotor roller ring (34), even when there is no pressureprevailing in the hydraulic cylinder (14).

It will be noted that in order for the tangential arm antifrictionroller (28) always to remain correctly positioned relative to thetangential arm roller rack (27) when the displacement-varying servomotor(68) causes the motor-pump peripheral rotor (29) to be off-centeredrelative to the motor-pump central rotor (3), rephasing means (197) maybe inserted between the peripheral rotor angular synchro ring (42) andthe central rotor angular synchro ring (11).

As shown by FIGS. 20 and 21, said means (197) may be made up of anintermediate rephasing gear (198).

It is easy to deduce from said figures that—the motor-pump central rotor(3) not rotating—when the peripheral rotor stator (65) is rotatedrelative to the motor-pump frame (2) by the displacement-varyingring-driving pinion (108), the rephasing toothed wheels (199) ofdifferent diameters included by the intermediate rephasing gear (198)rotate in the same direction as the peripheral rotor stator (65), but ata higher speed than said stator (65). As a result, the peripheral rotorcylindrical casing (32) rotates in the direction opposite the directionof rotation of the peripheral rotor stator (65), since the small toothedrephasing wheel (199) meshes with the angular synchronizing pinion (12)while the large toothed rephasing wheel (199) meshes with the peripheralrotor angular synchro ring (42), the two said wheels (199) being securedto one another in rotation and being supported by a same rephasing axle(200) secured to the peripheral rotor stator (65).

It will be noted that according to this example embodiment of therephasing means (197) according to the invention, the rotatingtransmission ratio established between the peripheral rotor stator (65)and the peripheral rotor cylindrical casing (32) is provided so that thetangential arm anti-friction roller (28) always remains in a position onthe tangential arm rolling track (26) such that the antifrictionfunction of the antifriction means (196) of which it is a component isperformed appropriately.

As can be deduced from FIGS. 10 and 11, the input/output spool valve(43) contributes greatly to the proper operation of the hydraulicmotor-pump (1) according to the invention in that the friction andmotor-pump oil leaks (114) of the latter are drastically limited by saidspool valve (43). According to the example used here to illustrate theoperation of the hydraulic motor-pump (1) according to the invention,said spool valve (43) is—according to that illustrated in FIGS. 10 and11—made up of a cylindrical stator (91) provided with an inner ductinput/output angular manifold (44) arranged over slightly less than 180°and placed axially between two outer duct radial force equalizinggrooves (90). Furthermore, said cylindrical stator (91) is also providedwith an outer duct input/output angular manifold (89) arranged to bediametrically opposite the inner duct input/output angular manifold(44)—also over slightly less than 180° —and placed axially between twoinner duct radial force equalizing grooves (45).

It will be noted that the outer surface of the cylindrical stator (91)that is subjected to the pressure of the motor-pump oil (114) containedby the inner duct input/output angular manifold (44) is equal to thetotal surface area subjected to said pressure from the two inner ductradial force equalizing grooves (45), such that said pressure does notgenerate any radial force on the cylindrical stator (91). This principleapplies similarly to the outer duct input/output angular manifold (89).

It will be noted that the twelve central rotor input/output orifices(12) are each connected to one of the twelve hydraulic cylinders (14)included by the motor-pump central rotor (3), are angularly distributedevery 30° in the stator cylinder (92) of said central rotor (3) insidewhich they emerge, and are axially aligned so as always to stay acrossfrom either the inner duct input/output angular manifold (44) or theouter duct input/output angular manifold (89) when the motor-pumpcentral rotor (3) is rotating, with the exception of their brief passageacross from an intermediate pressure zone (158) included by thecylindrical stator (91).

According to this example embodiment of the hydraulic motor-pump (1)according to the invention, the cylindrical stator (91), with the statorcylinder (92), produces sealing owing to the machining precision of saidstator (91) and said cylinder (92), but also owing to the spool valvegroove segments (46) included by said manifolds (44, 89) and saidequalizing grooves (90, 45) and that are also included by the two axialsealing grooves (93) that are respectively arranged on the cylindricalstator (91) near each of its axial ends.

FIGS. 14 to 17 diagrammatically show a developed surface of thecylindrical stator (91) of a hydraulic motor-pump (1) according to theinvention with fifteen hydraulic cylinders (14) angularly offset by 24°.It will be noted that the spool valve groove segments (46) define threepressure zones on the surface of said stator (91). The first is ahigh-pressure zone (159) made up of the inner duct input/output angularmanifold (44) and inner duct radial force equalizing grooves (45), whilethe second is a low-pressure zone (160) made up of the outer ductinput/output angular manifold (89) and outer duct radial forceequalizing grooves (90), or conversely, depending on whether themotor-pump central rotor (3) is leading or following, and on directionin which the motor-pump peripheral rotor (29) is off-centered relativeto said central rotor (3). The third zone is the intermediate pressurezone (158). FIGS. 14 to 17 being organized sequentially, they show thatthe angular sectors on which the inner duct input/output angularmanifold (44) and the outer duct input/output angular manifold (89) arerespectively arranged are calculated so that the two central rotorinput/output orifices (16) can never have one straddling thehigh-pressure zone (159) and the intermediate pressure zone (158) whilethe other is straddling the low-pressure zone (160) and the intermediatepressure zone (158). However, said sequence also shows that two centralrotor input/output orifices (16) can be found simultaneously straddlingthe high-pressure zone (159) and the intermediate pressure zone (158),or the low-pressure zone (160) and the intermediate pressure zone (158).This configuration allows the proper operation of the hydraulicmotor-pump (1) according to the invention while limiting the leaks ofmotor-pump oil (114) at the input/output spool valve (43) because saidoil (114) comprised in the high-pressure zone (159) is always separatedfrom the low-pressure zone (160) and the outside of the cylindricalstator (91) by at least one spool valve groove segment (46).

According to the example used to illustrate the operation of thehydraulic motor-pump (1) according to the invention, the spool valvegroove segment (46) is advantageously made up—as shown in FIGS. 12 and13—of two half-segments (95) made from a same material billet. These twohalf-segments (95) each have a segment flank (94) kept in axial and/ortangential contact with the cylindrical stator (91) by a segmentseparator spring (48) on the one hand, and a segment sealing line (49)that is radially in contact with the motor-pump central rotor (3) toform sealing on the other hand. In this configuration, said line (49) ispressed on said rotor (3) both by the thrust exerted by the pressurizedmotor-pump oil (114) contained by the cylindrical stator (91) and by asegment groove bottom spring (47). FIG. 12 shows that the half-segments(95), due to their segment force reacting shoulder (50) that cooperateswith the shoulder (162) arranged in the cylindrical stator (91), areprovided so that the segment sealing line (49) that they have is axiallypractically aligned with the contact zone between the segment flank (94)and the cylindrical stator (91), such that the pressure of themotor-pump oil (114) only has a small spray surface (161) to exert itsthrust on said half-segments (95).

The particular configuration described above and illustrated in FIGS. 12and 13 of the spool valve groove segments (46) according to theinvention guarantees good sealing between the cylindrical stator (91)and the stator cylinder (92), without generating excessive frictionlosses and wear, even when the hydraulic motor-pump (1) according to theinvention operates at high pressures and/or with a low viscositymotor-pump oil (114). Such a configuration thus effectively participatesin giving the motor-pump (1) a high output and durability irrespectiveof the displacement, the pressure, or the speed of rotation thatcharacterize its operation.

FIGS. 3 and 4 show an embodiment of the hydraulic motor-pump (1) wherethe latter is equipped with two central rotor bearings (5) and twoperipheral rotor bearings (36). Aside from the large diameter of saidbearings (5, 36), the latter are potentially subjected to strong loads,since the hydraulic pistons (13) can exert a high-intensity radial forceon the motor-pump peripheral rotor (29), said force being simultaneouslyexerted—by reaction—on the motor-pump central rotor (3). It can bededuced from this that the hydrodynamic bearings and the conventionalball bearings or roller bearings may be difficult to select for saidbearings (5, 36), at least without raising serious output and/ormechanical strength problems. That is why the central rotor bearings (5)and the peripheral bearings (36) are designed—according to thenon-limiting example embodiments described in FIGS. 3 and 4—to generatelimited friction losses and to durably withstand either high pressuresat high peripheral speeds, or high pressures at peripheral speeds so lowthat a sleeve bearing according to the prior art could not maintain thehydrodynamic lubrication rating essential for its operation. Below, theoperation of one of the two peripheral rotor bearings (36) is describedin more detail, the counterpart of the latter or the central rotorbearings (5) operating identically.

As particularly illustrated in FIG. 9, the peripheral rotor bearing (36)is made up of several peripheral rotor bearing rollers (37) that rollsimultaneously on the peripheral rotor bearing inner track (38) and onthe peripheral rotor bearing outer track (39). Approximately half ofsaid rollers (37) unevenly distribute the radial load to which theperipheral rotor bearing (36) is subjected. It will be noted that saidrollers (37) remain constantly equidistant from one another owing to theroller pinions (87) that they include at each of their ends, saidpinions (87) cooperating on the one hand with the peripheral rotorbearing inner rings (40), and on the other hand with the peripheralrotor bearing outer rings (41). FIG. 9 shows that the maintenance inaxial position of the motor-pump peripheral rotor (29) and theperipheral rotor bearing rollers (37) relative to the motor-pump frame(2) is ensured by the guide rail (85) included by the peripheral rotorbearing inner track (38) and the peripheral rotor bearing outer track(39), said rail (85) cooperating with the guide groove (86) included bythe peripheral rotor bearing rollers (37).

The peripheral rotor bearing rollers (37) having a large diameter, theHertz pressure that they exert on the peripheral rotor bearing innertrack (38) and the peripheral rotor bearing outer track (39) may remainwithin the mechanical strength limitations of the materials typicallyused by one skilled in the art to produce the rolling bearings, whereastheir maximum speed of rotation remains acceptable despite the largediameter of the peripheral rotor bearing (36) and the potentially highspeed of rotation of the motor-pump peripheral rotor (29). Furthermore,in addition to guaranteeing that the peripheral rotor bearing rollers(37) remain constantly equidistant from one another, the gear systemformed by the roller pinions (87), the peripheral rotor bearing innerrings (40) and the peripheral rotor bearing outer rings (41) imposes atrajectory on said rollers (37) perpendicular to the axis of rotation ofthe motor-pump peripheral rotor (29). These two functions, ordinarilyentrusted to the rolling bearings according to the prior art with ballcages or rollers, are thus advantageously performed by said gear system,said cages being both less precise and less durable than said systembecause they regularly collide with the balls or rollers that they grip,and generate friction losses at their point of contact with said ballsor said rollers.

Because the drive motor (123) rotates the motor-pump central rotor (3)using the central rotor power takeoff (4), the interest will be noted ofhaving fixed duct covering ball joints (59) by which the outerinput/output duct (58) is connected with the input/output spool valve(43) on the one hand, and with the motor-pump frame (2) on the otherhand. In fact, as shown in FIGS. 10 and 11, said covering rollingbearings (59) include a covering rolling bearing step (105) in the shapeof a truncated sphere that rests on a covering rolling bearing seat (64)and produces sealing on the one hand, and produces a rolling jointconnection on the other hand. The latter allows the input/output spoolvalve (43) to follow any misalignments or offsets to which themotor-pump central rotor (3) may be subjected relative to the motor-pumpframe (2), which in particular makes it possible to preserve a smalloperating play between the cylindrical stator (91) and the statorcylinder (92), said small play being necessary to guarantee good sealingbetween the stator (91) and said cylinder (92). In fact, this play beingable to be only several microns, it may not be obtained solely throughmachining precision of the set of parts that make up the fixed orvariable displacement hydraulic motor-pump (1) according to theinvention.

Furthermore, said covering rolling bearings (59) react the tractionforce to which the outer input/output duct (58) is longitudinallysubjected and which results from the pressure of the motor-pump oil(114) contained by said duct (58), while accepting the slight diametervariations of said duct (58) resulting from said pressure.

FIGS. 10 and 11 show an inner input/output duct (57) that includes twosliding covering half-ball joints (107) at each of its ends.Alternatively, said inner duct (57) may also include a fixed ductcovering ball joint (59) cooperating with a sliding covering half-balljoint (107) on the motor-pump frame side (2), and two sliding coveringhalf-ball joints (107) on the input/output spool valve side (43). Thisalternative embodiment allows said internal duct (57) to be axiallysecured to said frame (2). Irrespective of the chosen configuration,good sealing is ensured between the inner input/output duct (57) and theouter input/output duct (58) by the fixed duct covering ball joint(s)(59) and/or the sliding covering half-ball joints (107) both at themotor-pump frame (2) and at the input/output spool valve (43),irrespective of the positive or negative pressure difference betweensaid inner duct (57) and said outer duct (58), and irrespective of themicro-movements occurring between said frame (2) and said spool valve(43).

The central rotor power takeoff (4) rotating under the action of thedrive motor (123), it is possible to make the motor-pump peripheralrotor (29) more or less off-centered relative to the motor-pump centralrotor (3). To that end, the motor-pump management computer (70) includedby the hydraulic transmission device (63) of the motor vehicle (110) canpower the servomotor rotary electric motor (30) shown in FIGS. 1 to 6,so that the latter causes the displacement-varying ring (109) secured tothe peripheral rotor stator (65) by means of the displacement-varyingring driving pinion (108) to rotate in one direction or the other. Itwill be noted that the greater the off-centeredness of the motor-pumpperipheral rotor (29) is, the greater the hydraulic motor-pumpdisplacement (1) will be. If said off-centered state is zero, thedisplacement of said motor-pump (1) will be zero (FIG. 5). If thedirection of said off-centering is reversed, the motor-pump oil flowrate (114) passing in the inner input/output duct (57) and the outerinput/output duct (58) changes directions. These different possibilitiescover all of the control and adjustment needs of the hydraulictransmission device (63).

FIG. 23 shows a block diagram of the hydraulic transmission device (63)according to one particular and non-limiting configuration, while FIGS.28 to 31 show various examples of the implantation thereof in the motorvehicle (110) from among many other possibilities.

In the block diagram of FIG. 23, one can see that in addition to thevariable displacement hydraulic motor-pump (1) connected to the drivemotor (123) and the second variable displacement hydraulic motor-pump(125) connected to the drive wheels (124), the hydraulic transmissiondevice (63) includes a high-pressure accumulator (71) and a low-pressureaccumulator (118) able to supply motor-pump oil (114) to said variabledisplacement motor-pumps (1, 125) or to be supplied by the latter withmotor-pump oil (114) via the introductory pressure accumulator valve(112) or the outer duct high-pressure accumulator valve (128) for thehigh-pressure accumulator (71), and via the inner duct low-pressureaccumulator valve (129) or the outer duct low-pressure accumulator valve(130) for the low-pressure accumulator (118).

The block diagram of FIG. 23 also shows the accumulator locking valve(145) that may sealably isolate the high-pressure accumulator (71) ifthe hydraulic transmission device (63) remains unused for long periodsof time. In any case, said locking valve (145) remains continuously openwhen the hydraulic transmission device (63) is used. It can be deducedfrom said diagram that if the motor-pump oil (114) leaks from saidmotor-pumps (1, 125) during their operation—for example at theirinput/output spool valve (43) or their hydraulic pistons (13)—said oil(114) is recovered by the motor-pump oil reservoir (121) in which itflows. These motor-pump oil (114) leaks involve resupplying by thelow-pressure accumulator (118) of said motor-pumps (1, 125) with saidoil (114) in an equivalent quantity via the two low-pressure accumulatorcheck valves (143), the outlet of the first emerging in the innerinput/output duct (57) of said motor-pumps (1, 125) while the outlet ofthe second emerges in the outer input/output duct (58) included by saidmotor pumps (1, 125). In the diagram of FIG. 23, the hydraulicmotor-pump (1) according to the invention provides that the motor-pumpoil (114) that has leaked is periodically reintroduced in an equivalentquantity into the low-pressure accumulator (118) by the low-pressurepump (119) at the request of the motor-pump management computer (70),not shown in said diagram, said computer (70) being able—to that end—topower the low-pressure motor-pump (120).

It will be noted that, according to the particular embodiment of thehydraulic motor-pump (1) according to the invention as shown in theblock diagram of FIG. 23, the hydraulic transmission device (63)includes a pressure loss exchanger-dissipater (126) that may beconnected with the variable displacement hydraulic motor-pump (1)connected to the drive motor (123) or with the second hydraulicmotor-pump (125) connected to the drive wheels (124) via the inner ductexchanger-dissipater valve (131) or the outer duct exchanger-dissipatervalve (132).

It is also shown that accessories (165)—here shown by an airconditioning compressor (164) and an electric alternator (163)—may berotated by their secondary hydraulic motor (127) when the latter isconnected with the inner input/output duct (57) by the correspondinginner duct secondary motor valve (133).

It is possible—based on the block diagram of FIG. 23—to provide anon-limiting description of the main operating modes of the hydraulictransmission device (63) when it is used to propel a motor vehicle(110).

The motor vehicle (110) being stopped and its drive motor (123) idling,the displacement of the variable displacement hydraulic motor-pump (1)connected to the drive motor (123) is zero (FIG. 5), whereas forexample, the displacement of the second hydraulic motor-pump (125)connected to the drive wheels (124) is maximal (FIG. 6).

If the driver of the motor vehicle (110) partially pushes down theaccelerator pedal (151), the management computer of the drive motor(170) that was shown in FIGS. 28 to 31 increases the load and/or speedof the drive motor (123) whereas at the same time, the motor-pumpmanagement computer (70) controls the displacement-varying servomotor(68) of the hydraulic motor-pump (1) connected to the drive motor (123)so as to give a displacement to said motor-pump (1), then graduallyincrease said displacement. Rotated by the drive motor (123), thehydraulic motor-pump (1) operates in “pump” mode and sucks up motor-pumpoil (114) at a low pressure in the outer input/output duct (58) to nextdischarge it under high pressure in the inner input/output duct (57),while the second hydraulic motor-pump (125) operates in “motor” mode torotate the drive wheels (124) by admitting said oil (114) under highpressure from the inner input/output duct (57) to discharge it under lowpressure in the outer input/output duct (58). This results intransmitting the mechanical work produced by the drive motor (123) tothe drive wheels (124), the motor vehicle (110) gradually being set inmotion while at each moment, the ratio between the displacement of thehydraulic motor-pump (1) connected to the drive motor (123) on the onehand, and the displacement of the second hydraulic motor-pump (125) onthe other hand, determines the transmission ratio between said motor(123) and the drive wheels (124), corrected for example for thetransmission ratio of a differential axle assembly (171) insertedbetween said second motor-pump (125) and said wheels (124) as shown inFIG. 28.

When the driver of the motor vehicle (110) is performing an ordinaryjourney, the motor-pump management computer (70) simultaneously controlsthe displacement of the hydraulic motor-pump (1) connected to the drivemotor (123) and that of the second hydraulic motor-pump (125) such thaton the one hand, the energy output of said motor (123) is always as highas possible—by forcing said motor (123) to operate as close as possibleto the speed and load points where its actual specific consumption islowest—and on the other hand, the energy output of the hydraulictransmission device (63) is also as high as possible, in particular byfinding the best compromise between operating pressure and flow rate ofsaid motor-pumps (1, 125), so as to minimize the total energy lossescreated by the leaks and/or friction and/or pressure losses inevitablygenerated by said motor-pumps (1, 125).

It will be understood that in this context, the management computer ofthe drive motor (127) and the motor-pump management computer (70) shownin FIGS. 28 to 31 cooperate so that the combined output of the drivemotor (123) and the hydraulic transmission device (63) is as high aspossible, and the fuel consumption of the motor vehicle (110) is as lowas possible while providing the same service. It will be noted that thebackward movement of the motor vehicle (110) may be obtained, forexample, by reversing the direction of the off-center of the motor-pumpperipheral rotor (29) of the second hydraulic motor-pump (125), relativeto its motor-pump central rotor (3).

If the driver pushes the accelerator pedal (151) of the motor vehicle(110) all the way down, the management computer of the drive motor (170)immediately increases the load of the drive motor (123) to its maximum,while the motor-pump management computer (70) determines, for thehydraulic transmission device (63), a transmission ratio between saidmotor (123) and the drive wheels (124) such that said motor (123) is atits maximum power rating. Immediately afterward, or even at the sametime, the motor-pump management computer (70) causes the acceleration ofthe motor vehicle (110) by gradually reducing the transmission ratio ofthe hydraulic transmission device (63) while using the full power of thedrive motor (123). This is obtained by controlling the displacement ofthe hydraulic motor-pump (1) and/or that of the second hydraulicmotor-pump (125). Due to the permanent maximum power delivered by thedrive motor (123) during this acceleration, and due to the lack ofdiscontinuity in the traction of the motor vehicle (110), the actualacceleration of said vehicle (110) is sharper than if the latter wereequipped with a discrete ratio transmission, whether a manual orautomated transmission, with single or dual clutch, or an automatictransmission with planetary gear sets coupled to the drive motor (123)by a disc clutch or a hyperkinetic converter.

When the driver wishes to slow the speed of the motor vehicle (110), hereleases the accelerator pedal (151) thereof shown in FIG. 32. Thehydraulic transmission device (63) can then recover part of the kineticenergy from said vehicle (110). To that end, the management computer ofthe drive motor (170) for example immediately causes the drive motor(123) to idle, while the motor-pump management computer (70) controlsthe displacement-varying servomotor (68) of the hydraulic motor-pump (1)connected to said motor (123) so that the displacement of saidmotor-pump (1) is zero, as shown in FIG. 5. In parallel, the motor-pumpmanagement computer (70) simultaneously opens the inner ductlow-pressure accumulator valve (129) and the outer duct high-pressureaccumulator valve (128) such that the second hydraulic motor-pump (125)operates in “pump” mode, being driven to that end by the drive wheels(124), and sucks up motor-pump oil (114) at a low pressure in the innerinput/output duct (57), then discharges said oil (114) under highpressure into the outer input/output duct (58). In so doing, said secondmotor-pump (125) transfers the motor-pump oil (114) from thelow-pressure accumulator (118) to the high-pressure accumulator (71).Consequently, the pressure of the motor-pump oil (114) contained in thelow-pressure accumulator (118) decreases, while the pressure of themotor-pump oil (114) contained in high-pressure accumulator (71)increases due to the respective stiffness of said accumulators (118,71), which results from the stiffness of the nitrogen contained in theirgas compartment (116). According to this example embodiment, thepressure in the low-pressure accumulator (118) for example variesbetween three bar, when the accumulator separator piston (72) of saidaccumulator (118) is at the bottom dead center, and six bar when saidpiston (72) is at the top dead center, whereas regarding thehigh-pressure accumulator (71), these pressure values may—as anon-limiting example—respectively be one thousand and two thousand bar.It will be noted that during the deceleration of the motor vehicle(110), the motor-pump management computer (70) continuously adapts thedisplacement of the second hydraulic motor-pump (125) so as on the onehand to adjust the intensity of said deceleration, and on the otherhand, to account for the stiffness of the low-pressure accumulator (118)and that of the high-pressure accumulator (71). Thus, during aconstant-intensity deceleration, the pressure of the motor-pump oil(114) at the output of the second hydraulic motor-pump (125) tends toincrease with the distance traveled by the motor vehicle (110), whereasthe pressure of the motor-pump oil (114) at the input of said secondmotor-pump (125) tends to decrease.

It will be noted that other than releasing the accelerator pedal (151)of the motor vehicle (110) to slow the latter, the driver of saidvehicle (110) may also press on the brake pedal (150) of said vehicle(110), shown in FIG. 32, so that the deceleration of the latter issharper. In that case, the hydraulic transmission device (63) maycompletely or partially replace the disc brakes (172) of said vehicle(110), which have been shown in FIGS. 28 to 31, so that at least part ofthe kinetic energy of said vehicle (110) is not dissipated in the formof heat by said brakes (172), but stored in the high-pressureaccumulator (71) in the form, for example, of compressed nitrogen. Inthat context, at least one sensor (not shown) may provide information tothe motor-pump management computer (70) on the position of the brakepedal (150) and/or on the force that the driver is exerting on saidpedal (150), such that if the power of the second hydraulic motor-pump(125) and the storage capacity of motor-pump oil (114) of thehigh-pressure accumulator (71) allow it, the motor vehicle (110) is, asa priority, braked by the second motor-pump (125) before said brakes(172) intervene additionally or to replace the braking done by saidsecond motor-pump (125). In any case, this configuration requires aso-called “smart” brake pedal (150) operating using a principle similarto that of the so-called “decoupled brake pedal” concept jointlydeveloped by the companies “Renault” and “Bosch” for the “Zoe” electricvehicle produced by “Renault”.

It will be noted that the braking of the motor vehicle (110) is not theonly source of mechanical work that makes it possible to store energy inthe high-pressure accumulator (71). In fact, the mechanical workproduced by the drive motor (123) can be stored similarly. For example,when the motor vehicle (110) is traveling, part of the motor-pump oil(114) flow leaving the hydraulic motor-pump (1) connected to said motor(123) can drive the drive wheels (124) of said vehicle (110), whereasanother part can be stored in the high-pressure accumulator (71). Tothat end, the motor-pump management computer (70) simultaneously opensthe outer duct low-pressure accumulator valve (130) and the inner ducthigh-pressure accumulator valve (112), and controls both thedisplacement of the hydraulic motor-pump (1) connected to said motor(123) and that of the second hydraulic motor-pump (125), so as to beable to propel the motor-vehicle (110) as desired by the driver of saidvehicle (110) on the one hand, and to fill the high-pressure accumulator(71) taking the stiffness of the nitrogen contained by the gascompartment (116) into account on the other hand.

This strategy makes it possible, in certain cases, to operate the drivemotor (123) under a higher load than necessary to propel the motorvehicle (110) such that said motor (123) develops a better output. Theexcess work produced by said motor (123) is thus stored in thehigh-pressure accumulator (71), which may later supply the secondhydraulic motor-pump (125) with motor-pump oil (114) to propel saidvehicle (110) without it being necessary to use the drive motor (123).Furthermore, it is possible to load the drive motor (123) intermittentlyto move the motor vehicle (110) by alternating between short operatingphases of said motor (123) at maximum output and a relatively high load,during which the motor (123) ensures both the propulsion of said vehicle(110) and the filling of the high-pressure accumulator (71), and idlephases of said motor (123), during which only said accumulator (71)supplies the energy necessary to propel said vehicle (110) via thesecond hydraulic motor-pump (125). According to this last strategy, themotor vehicle (110) may be equipped with an acoustic transmitter (173)as illustrated in FIGS. 28 to 30, which reproduces—through a suitablemixture of the acoustic waves that are propagated in the passengercompartment of the motor vehicle (110)—the noise from the drive motor(123) operating continuously, so as to offer the passengers of saidvehicle (110) the best possible comfort. It will be noted that thehigh-pressure accumulator (71) may also be filled with motor-pump oil(114) by the drive motor (123 when the motor vehicle (110) is stopped.

Once the motor vehicle (110) is brought to a reduced speed or stopped,the kinetic energy of the motor vehicle (110) and/or the mechanical workproduced by the drive motor (123) stored in the form of pressurizednitrogen in the high-pressure accumulator (71) can be reused to fulfillvarious strategies. For example, it is possible to move the motorvehicle (110) over several meters or tens of meters without using thedrive motor (123) if the latter is stopped. To that end, the motor-pumpmanagement computer (70) simultaneously opens the outer ductlow-pressure accumulator valve (130) and the inner duct high-pressureaccumulator valve (112) and adjusts the displacement of the secondhydraulic motor-pump (125) to meet the movement needs of the motorvehicle (110), while giving the displacement of the hydraulic motor-pump(1) connected to said motor (123) a zero value (FIG. 5). It is alsopossible to start the drive motor (123) without using an electricstarter. To that end, the motor-pump management computer (70)simultaneously opens the inner duct low-pressure accumulator valve (129)and the outer duct high-pressure accumulator valve (128) and adjusts thedisplacement of the hydraulic motor-pump (1) connected to said motor(123) to just what is necessary to start said motor (123) while giving azero value to the displacement of the second hydraulic motor-pump (125)(FIG. 5).

Furthermore, to propel the motor vehicle (110), the energy stored in thehigh-pressure accumulator (71) may reinforce that produced in mechanicalform by the drive motor (123). This strategy may be justified in case ofvery strong acceleration of the motor vehicle (110), where it isadvantageous to add the power of said high-pressure accumulator (71) tothat of said motor (123). To that end, the management computer of thedrive motor (170) having increased the load of the drive motor (123) toits maximum and said motor (123) being placed at its maximum powerrating, the motor-pump management computer (70) simultaneously opens theouter duct low-pressure accumulator valve (130) and the inner ducthigh-pressure accumulator valve (112), such that the high-pressureaccumulator (71) delivers a motor-pump oil flow rate (114) that is addedto that produced by the hydraulic motor-pump (1) connected to said motor(123). The sum of the two flow rates is thus converted into mechanicalwork by the second hydraulic motor-pump (125), the displacement of whichis adjusted accordingly by the motor-pump management computer (70), saidwork being transmitted to the drive wheels (124) of the motor vehicle(110).

The pressure loss exchanger-dissipater (126) shown in the block diagramof FIG. 23 also participates in optimizing the energy balance of themotor vehicle (110), in addition to potentially contributing to reducingthe cost thereof and the maintenance of the disc brakes (172) andimproving driving comfort for the driver.

Said exchanger-dissipater (126) may for example be used to acceleratethe temperature increase of the drive motor (123). To that end, whetheror not the motor vehicle (110) is moving, the management computer of thedrive motor (170) increases the load and/or speed of said motor (123),while at the same time, the motor-pump management computer (70) opensthe inner duct exchanger-dissipater valve (131), which results inforcing the motor-pump oil (114) expelled into the inner input/outputduct (57) by the hydraulic motor-pump (1) connected to the drive motor(123) to pass into the exchanger-dissipater inner duct (135) and intothe throats (166), the latter cooperating in creating a pressure drop.The additional load imposed by the management computer of the drivemotor (170) on the drive motor (123) is thus converted into anadditional pressurized motor-pump oil flow (114) that is converted intoheat inside the exchanger-dissipater (126) under the effect of thepressure loss constituted by the exchanger-dissipater inner ducts (135)and the throats (166), before returning—via the dissipater check valve(169)—to the intake of the hydraulic motor-pump (1) connected to thedrive motor (123), to be sucked back up therein. The motor-pump oil(114) having heated up while passing through the exchanger-dissipaterinner ducts (135) and the throats (166), said oil (114) next transferspart of its heat to water contained in a cooling circuit included by thedrive motor (123), via the outer dissipater heat exchange surface (136).Said water heats rapidly while the lubricating oil of the drive motor(123) also fluidizes rapidly, which limits the friction losses and heatlosses generated by said motor (123). Furthermore, the load of saidmotor (123) being high, the temperature of its exhaust gases is alsohigh, which allows a rapid temperature increase of its three-waycatalytic converter so as to potentially reduce the quantity ofpollutants emitted by said motor (123). Furthermore, the passengercompartment for the motor vehicle (110) propelled by said motor (123) israpidly heated in the wintertime, which promotes the comfort of saidpassengers.

To slow or even stop the motor vehicle (110), the pressure lossexchanger-dissipater (126) may advantageously replace the motor brakethat may be produced by the drive motor (123) when it is driven by thedrive wheels (124) and/or the disc brakes (172), particularly when thehigh-pressure accumulator (71) can no longer admit pressurizedmotor-pump oil (114) because it is full.

To that end, when the driver releases the accelerator pedal (151) orpushes on the brake pedal (150), the management computer of the drivemotor (170) for example causes the drive motor (123) to idle, while themotor-pump management computer (70) places the displacement of thehydraulic motor-pump (1) connected to said motor (123) at a zero value(FIG. 5). In parallel, the motor-pump management computer (70) opens theouter duct exchanger-dissipater valve (132) such that the secondhydraulic motor-pump (125) operates in “pump” mode, being driven to thatend by the drive wheels (124), and sucks motor-pump oil (114) at a lowpressure into the inner input/output duct (57), then discharges said oil(114) under high pressure at the inlet of the pressure lossexchanger-dissipater (126). Said oil (114) passes through, then leavessaid exchanger-dissipater (126) after having been heated, then cooledtherein, then returns into the inner input/output duct (57) via thecorresponding dissipater check valve (169) to be sucked therein again bythe second hydraulic motor-pump (125).

The strategy described above makes it possible to use the kinetic and/orgravitational energy of the motor vehicle (110) to effectively heat themotor and/or the passenger compartment. This strategy further makes itpossible to limit the wear and heating of the disc brakes (172), forexample during long descents, and optionally to provide smaller discbrakes (172).

FIG. 31 illustrates one of the most remarkable applications of thehydraulic transmission device (63), which consists of coupling it withan internal combustion low-pressure turbine engine (174) according tothe configuration described in French patent application no. FR 12 59827belonging to the applicant, said turbine engine (174) then making up thedrive motor (123) instead and in place of the reciprocating controlledignition internal combustion heat engine previously used to illustratethe operation of the fixed or variable displacement hydraulic motor-pump(1) according to the invention.

According to this application, the multi-turbine reducing gear poweroutput shaft (175) of the multi-turbine group (176) included by theinternal combustion low-pressure turbine engine (174) is connected tothe central rotor power takeoff (4) to be able to rotate the motor-pumpcentral rotor (3) of the variable displacement hydraulic motor-pump (1)comprised by the hydraulic transmission device (63). FIG. 31 shows themain components of the internal combustion low-pressure turbine engine(174) that are described and/or claimed in French patent application no.FR 12 59827, which are a turbine engine air intake mouth (177) and itsturbine engine intake air filter (178), a low-pressure turbocharger(179), an intermediate turbocharger cooler (180), a high-pressureturbocharger (181), an air/regenerative countercurrent mixture exchanger(182), a continuous combustion chamber (183), a pollutant post-treatmentcatalyst (184), an expansion power turbine gas-vapor intake duct (185),expansion drive turbines (186) that are part of the multi-turbine group(176) and whereof the expansion drive turbine shaft (187) drives amulti-turbine reducing gear ring (188) via a turbine driving pinion(189), an expansion turbine exhaust manifold (190), an expansion powerturbine gas-vapor exhaust duct (191), an exhaust line (192), and anexhaust line outlet (193).

In this context, the hydraulic transmission device (63) makes itpossible to make the internal combustion low-pressure turbine engine(174) compatible with driving of the motor vehicle (110). In fact, saiddevice (63) makes it possible to store, in the high-pressure accumulator(71), a large part of the kinetic energy from the expansion driveturbines (186) during the speed variations of the latter, and toaccommodate the response time of said turbines (186) by using or notusing the energy stored in said accumulator (71) to restart the motorvehicle (110) without consequences for the driving comfort of saidvehicle (110). Furthermore, the particularities specific to Frenchpatent application no. FR 12 59827 and those of the fixed or variabledisplacement hydraulic motor-pump (1) according to the invention make itpossible to accommodate the relatively low speed of rotation range overwhich the expansion drive turbines (186) deliver their best output. Infact, this particularity is managed on the one hand by the multi-turbinegroup (176), which provides a gear reduction ratio between eachexpansion drive turbine (186), and the multi-turbine reducing gear poweroutput shaft (175) adapted to each said turbine (186), said ratio beingdetermined by the multi-turbine reducing gear ring (188) and the turbinedriving pinion (29) associated with each said turbine (186), and on theother hand, by the hydraulic transmission device (63) that may, at anytime, transmit the power produced by the expansion drive turbine(s)(186) to the drive wheels (124) irrespective of the speed of the latterrelative to that of the or said turbine(s) (186).

The characteristics of the internal combustion low-pressure turbineengine (174) according to French patent application no. FR 12 59827combined with those of the hydraulic transmission device (63) as set outby the fixed or variable displacement hydraulic motor-pump (1) accordingto the invention thus make it possible to produce motor vehicles (110)with a very low fuel consumption.

FIGS. 25 to 27 illustrate the operation of the high-pressure accumulator(71) and/or the low-pressure accumulator (118) whereof the oilcompartment (117) is arranged so as to be able to store the motor-pumpoil (114) under a very high pressure, for example 2000 bar, in completesafety. It will be noted that said accumulators (71, 118) can never becompletely emptied of their oil, which is not novel in itself. However,the fixed or variable displacement hydraulic motor-pump (1) according tothe invention provides that when the accumulator separator piston(72)—due to the emptying of the motor-pump oil (114) of thehigh-pressure accumulator (71) and/or the low-pressure accumulator(118)—has come into contact with the high stiffness spring plunger (77)as shown in FIG. 26, then continued its travel toward the accumulatorclosing valve (73), said piston (72) has next pressed said gate (73) onthe accumulator gate seat (74) using a high stiffness resisting spring(76) inserted between said plunger (77) and said gate (73). Thisparticular arrangement results in closing of the oil compartment (117)when the latter is largely emptied of the motor-pump oil (114) that itcontains while preserving a small pressure difference between said oilcompartment (117) and the gas compartment (116), such that theaccumulator separator piston (72) never undergoes any strong pressuredifferential. This particularity makes it possible to produce saidpiston (72) using a light material with a simple accumulator pistonjoint (122), without incurring any risk of destruction of said piston(72) or risk of significant motor-pump oil leaks (114) between the oilcompartment (117) and the gas compartment (116).

The possibilities of the fixed or variable displacement hydraulicmotor-pump (1) according to the invention are not limited to theapplications described above, and it must furthermore be understood thatthe preceding description has only been provided as an example and in noway limits the field of said invention, and it would not be beyond thescope of said invention to replace the described embodiment details withany other equivalent means.

1. A pressure accumulator comprising at least one accumulator separatorpiston (72) able to move sealably in a blind accumulator cylinder (113),said piston (72) delimiting, with said cylinder (113), a gas compartment(116) containing a pressurized gas (115) and an oil compartment (117)containing a motor-pump oil (114), the latter compartment (117) beingable to be connected with an input/output duct, characterized in thatthe oil compartment (117) includes an accumulator closing gate (73) thatthe accumulator separator piston (72) can press on an accumulator gateseat (74) by pushing on a high-stiffness gate spring (76) insertedbetween said piston (72) and said gate (73), so as to sealably isolatesaid compartment (117) from the input-output duct, said gate (73)cooperating—opposite the high-stiffness gate spring (76)—with alow-stiffness gate spring (75) that tends to separate said gate (73)from said seat (74).
 2. The pressure accumulator according to claim 1,characterized in that the accumulator separator piston (72) can push onthe high-stiffness gate spring (76) using a high-stiffness springplunger (77) that is guided in longitudinal translation by a gate guideand plunger (78) secured to said pressure accumulator (71, 118), saidgate guide (78) also guiding the accumulator closing gate (73) andincluding a plunger stop (79) that determines the maximum movement ofthe high-stiffness spring plunger (77) toward the accumulator separatorpiston (72).
 3. The pressure accumulator according to claim 2,characterized in that the gate guide and plunger (78) includes at leastone gate guide radial orifice (80) that connects the oil compartment(117) with the accumulator gate seat (74) so as to allow the oil (114)to circulate in the input-output duct and said oil compartment (117).